Update 11/9/2011: Been awhile but I have some news, ShortyUSA has run out of Black Widow's for quite a long time now. The gearbox is not strong enough to support stronger springs and powerful motors. I recommend getting an entirely new gearbox if you wish to upgrade. This is instructable may not apply to everyone who bought a broken Black Widow from Shorty, you may have to buy a new o-ring depending on the problem.
BE means Both Elephant which is an airsoft company in China.
MAKE SURE YOU LOOK AT ALL PICTURES, THERE ARE VERY IMPORTANT NOTES!
Step 1: Getting Ready
You can buy these guns for only $10! Shorty USA wants to get rid of them because they are all broken. But what I found out was that the o-ring was placed in the wrong spot.
Update 11/9/2011: Goggles
Step 2: Taking the Cover Off
This is where you need one of those choices: 1, 2, or 3.
1. Cut the chopsticks thin enough to fit through the holes of pins (the things that hold the gun together). Put the chopstick on top of the pin and hammer it out. Refer to the instruction manual to take it apart.
2. Use the steel rod and push down onto the pins until they come out. Refer to the instruction manual to take it apart.
3. Same thing as number 2. Push down and refer to the instruction manual.
Use the screwdriver to take off the cap of the handle. Refer to picture for reference.
Step 3: Opening the Gearbox
Now this is probably the hardest part. Make sure that you don't lose any parts. And yes it is normal if it is very greasy. The smell is also caused by this grease. You can wipe some off if its too unbearable. Use the screwdriver to take out the screws.
Step 4: Moving the O-ring Back and Reassembly
Take the black tube out and pull the beige tube out of the black one. Now look at the black rubber circle thing. Pull it over the notch, the one behind it. If yours is really malformed then buy a new one. Make sure everything is in place. Refer to diagram link. After that reassemble everything and wipe off excess grease.
Step 5: Test Time
Here is a link for a diagram if you need to know where the gears were placed: http://images.google.com/imgres?imgurl=http://img201.imageshack.us/img201/2994/aegdiagramow4.gif&imgrefurl=http://www.airsoftforum.com/board/lofiversion/index.php/t49427.html&usg=__1jCjVOhHRhfF8NFlYg4z7i07Y_I=&h=400&w=550&sz=132&hl=en&start=21&um=1&tbnid=gGgRhPgn4IGISM:&tbnh=97&tbnw=133&prev=/images%3Fq%3Ddiagrams%2Bof%2Ban%2Baeg%26hl%3Den%26rlz%3D1T4GWYE_enUS249US250%26sa%3DN%26um%3D1