Step 1: Dissasembly
1. Remove the four screws on the back side of the psp, plus two on the top and one on the bottom. The first four screws are identical, but the upper ones and lower one are different. Don't mix them up.
2. Lift the front cover. Pay attention to the start button, as it tends to fall off and wander away. Then, use a small clip or screwdriver to take off the home bar. Don't pull its cable, just take it off the screen.
3. Lift the screen and pivot it until you see the cables. Gently lift the tabs that hold the cables upwards and pull them off. Pull the home screen's cable upwards, then pull the cable off.
4. Remove the screen. Then, remove the screws nearby the triggers. After this, you can take both of the triggers out.
5. Remove the metal thingy that is located at the top edge of the psp.
6. Disconnect the dpad in the same way you disconnected the screen. Take the screw out as well. Remove any memory card and leave the access to the memory card fully open. Take the Dpad off. the R trigger button is slightly glued, but you can just peel it away.
7. Disconnect everything else from the motherboard and remove it by lifting the lower side up, then pulling it away.
8. Remove the metal shield (a thim metal sheet under the motherboard)
Step 2: Prepare Speaker Location
Step 3: Speaker Holes
Just glue the template to the PSP with a light glue (cheap bar glue worked for me), drill away, and peel the template off.
Step 4: Electrical Connection
Read the following very carefully before attempting to do the project
The psp built in amplifier cannot power all three speakers, so you have to ditch one of them. I decided to leave out the right one. If you want to keep all three, see the last step. Make sure the replacement speaker (the new one you have) has an impedance of 8 ohms or higher (>8) if lower, you may burn the psp's audio amp.
1. Hot glue the speaker so it doesn't move.
2. Solder a pair of THIN cables to the speakers.
3. Route the cables as shown.
-Through the metal shield. When you place the metal shield back, make sure it does not touch the speaker's led. If you feel uncomfortable, place a small piece of electrical tape to prevent the speaker's contacts from touching the metal shield.
-Then reinstall the motherboard and keep following
4. Solder them to the right speaker terminals.
5. Close everything
Step 5: Enjoy
Step 6: Bonus
Then you need a small amplifier. Something like an LM386 or TL072, placed besides the speaker, with no amplification (just buffering the Psp speaker's signal) . The wifi switch case is equivalent to ground, and the 5v supply can be found above the two resistors that power the wifi and sd card led. My right speaker had already died of a natural cause, thus I did not gained anything by taking this route; but thats how I would do it if it still worked.
I only recommend implementing the amplifier to someone who has soldered before and knows about electronics, because the amplifier 5v supply line is difficult to solder. (its very small) Thus, I won't post a throughout schematic; after all its just an noninverting amplifier with no gain followed by a capacitor and the speaker. If you don't know what this means, you should probably stay with the basic hack and loose one of the two default speakers.