OK, to strip down the gp2x, you'll need 2 tools, a hammer and a chisel. simply turn the gp2x upside down and place the chisel at the left hand side, hit the chisel with the hammer until it's severed the two screws at the left hand side. repeat for the right hand side.
While you have the gp2x open, you may want to remove some of the "coverings" on the chips, this will make you able to overclock to 300+MHz. to do this, put the edge of your chisel just above the silver pins on the chip, then hit it sideways with your hammer, until the black covering is removed. repeat for all the chips you can see.
sorted!