I noticed there were no instructables on this site for restringing an electric guitar, there is only one is for an acoustic and the steps are a little different. I thought i would post one with tips that will allow you to restring your guitar in standard tuning (e,B,G,D,A,E) without messing with a tuner. The without a tuner part of the instructable will only work if you are not tone deaf, perfect pitch is not required, only an ability to match two of the same notes. You can also follow the main portion of this instructable if you have a tuner and just need help restringing your electric guitar.
What you'll need:
-pack of new strings
-small Phillips screwdriver
Step 1: Remove the Back Panel
Start out by using your small screwdriver to remove the small screws on the panel on the back of the guitar body. The screws might be tough to loosen up, but I like to unscrew the middle two first, then do an x pattern for the other four. It would probably be possible to restring the guitar without completing this step, however this will make it much easier to access the back. Doing so should reveal a setup similar to the one in the second image below. The holes will become important later on in this instructable, as they are where the strings are "housed"
Step 2: Loosen the Low E String
Start out by loosening only the low E string by turning the tuning peg knob (shown in second picture). The string should be loose enough so that you can easily fit the wire cutters in to cut it and you won't have to worry about any recoil when the string is cut.
Step 3: Cut and Remove the Low E String
Once the string is reasonably loose, use the wire cutters to cut the string. You can then feed half the string through the previously shown hole in the back of the guitar. It might be difficult pushing the string through the hole in the back so twisting while pushing should allow the string to be removed more easily. You could also use the small screwdriver that you used to remove the back panel to help loosen the end of the string. The other half can then be unwrapped from the tuning peg and removed. This string should be the toughest to remove due to the thickness of the string.
Step 4: Insert New String
You can then take the new string from the bag and feed it through the same hole in the back of the guitar that the old one came out of. Pull the string all the way through until the colored end loop is snug inside the hole. After that, take the loose end of the string and feed it across the neck and wrap it around the tuning knob 2 to 3 times. Due to the thickness of the string, you may only be able to wrap the string around twice. After wrapping it around the tuning knob, then feed the end through the hole in the tuning knob. After feeding the wire through the hole you can then tighten the string using the knob until you think its close to in tune. When the string is in tune, playing with the fifth fret pressed down should sound the same as playing open on the A string (one string down), because they are the same note.
Step 5: A and D Strings
For the next two strings, which are the A and D strings, repeat the process of replacing the old strings with the new strings, one at a time. Just like on the low E string, play the fifth fret and compare it to the string below it. You should also make sure that the previously replaced strings stay in tune. Making sure the previously replaced strings stay in tune is necessary because the new strings go out of tune much more easily than the ones that have been on for a while.
Step 6: G String
The next string down, which is G can be replaced the same way as outlined in the previous step, but the tuning step is a little different. When tuning the G string, the procedure is a little different because you have to play the fourth fret on the G string to play the B note which corresponds to playing the next string down open.
Step 7: B String
For the B string (2nd from bottom), follow the same procedure as the other strings for removing the old string replacing it with the new string. The procedure for tuning the B string is the same as the first three strings, compare the fifth fret of the B string to the the open high e string (bottom string).
Step 8: High E String
You should now have all the strings replaced except the last one, which is the high e string. The process for replacing the e string is the same as the other string, but of course for this string it cannot be compared to a string lower on the neck. To compensate for this, you'll have to compare it to the previously replaced strings. Played open should be the same as playing the fifth fret of the B as can be inferred by just going about the same routine but doing it in reverse. Playing with the fret first pressed down on the high e string should also be the same as playing with the sixth fret pressed down on the B string.
Step 9: Tune Check
Now that you have all your strings on, you might not be sure if they are all in the tune. A good way to tell is by playing a scale, either major or pentatonic. The attached image is two seven patterns of the G major scale. When played forward, the scale should sound like do, re, mi, fa, sol, la, ti, do. When played in reverse it should sound like "Joy to the World".
Step 10: Replace Back Panel
You can now put the back panel back on the back of the guitar, using the same x pattern that you used to remove the screws. Ensure that the panel is tight or it could result in excess vibration especially noticeable when playing the low E and A strings.
Step 11: Trim the Strings
You should also have a lot of excess string sticking out the edge of the tuning pegs you can now cut off that excess, because it is no longer needed and just gets in the way when storing your guitar. After you cut the ends off be careful of the end of the string as it is very sharp so you could be cut by it if it remains too long and you graze against it. You should now have an in-tune guitar that looks just like it did before you replaced the strings.