Overall, this isn't very difficult and should only take about a half-an-hour, as mentioned earlier. I'm going to show you how to do it on a Version 4 PS2. (what version is my PS2?)
Step 1 is to unplug everything (cables, controllers, memory cards, etc.) If you have a hard drive or network card installed, you should not have to take them out. Next, pry up the little plates covering the case screws on the bottom of the unit with the blade screwdriver or very carefully with the knife. Then, unscrew all screws that were under each cover. This is generally 6 to 8 screws total. Store all covers and screws in the plastic bag.
You'll have to carefully cut through the tape holding through the case together on the back of the unit with the knife. This tells Sony that you've opened the case and voided your warranty. If you do not wish to continue, replace all screws, screw covers, and twiddle your thumbs. Cut carefully where there is a gap in the casing so that the knife is not damaging the case.
The top half and bottom half of the case should now separate. Carefully tilt the top half of the case backward as shown in the next image. Be very careful of the silver ribbon cable that's connected to the power and eject switches. On many PS2s it is taped to the top of the CD/DVD drive with a white sticker. Take the sticker off.
Now that the case is out of the way, and so is the silver ribbon cable... unscrew the 4 tiny screws on the top of the CD/DVD drive with the smaller Philips head screwdriver. Store these screws in the plastic bag.
This allows disc-swapping access to the CD/DVD drive by removing the top cover.
Place the CD/DVD drive's top cover back on the driver properly and place the top half of the case back on the PS2. Make sure that the silver ribbon cable is not caught on the CD/DVD drive, bent, or squished in any strange way. It is very delicate and needs to be handled with care.
Get out the electrical tape... we're going to use it to keep the case together and for easy swapping access!
Apply two 3 or 4 inch pieces of electrical tape as shown. Apply the left piece to the bottom of the unit, then fold it over up onto the back. This will hold the top and bottom halves of the case together on that side. Do the same on the right side of the unit, but instead just apply the entire piece without any folding. (you'll fold it to separate the halves) Fold a tiny bit at the top of each piece down over the sticky side to make it easier to pull the tape off a single half of the case when swapping discs.
Last, apply a long piece of tape under the DVD/CD drive but above the USB/iLink connectors as shown. This is barely visible if you're using black tape, and allows the top and bottom halves of the case to swing apart when the pieces of tape on the back are folded down.
Ta-da! This allows you to swap discs for just $25. (unless you had to buy supplies... but then again it's still pretty cheap)
I've attached a short MPEG-4 video of me using the SwapDisc to load a backed-up copy of "Grand Theft Auto: San Andreas". You'll need Quicktime to view it.
smash's PS2 Swap Disc Mod (in action!) MPEG-4 Video
If you'd like to link to this video, please link to this post instead. It's URL is:
smash's world: easily mod your PS2 in 30 minutes... (with no soldering!)*_*the offical homepage of Ben Guild (smash)
You can also find this post on digg:
http://www.digg.com/gaming/easily_mod_your_PS2_in_30_minutes..._(with_no_soldering_)
taken from smash's world.