You don't need much to get a classic Mac open. You can
very easily make a long-handled torx driver suitable
for taking apart Macs.
You need:
T-15 torx bit
Bic round stic ballpoint pen
Hexagonal pencil (new/unsharpened)
Take the ink cartridge and the end stop out of the pen
leaving a plastic tube. Firmly insert the Torx bit
into one end of the pen, and the pencil into the other
end. They will wedge into the pliable pen barrel
plastic and stay firmly. This combination is long
enough to remove all the torx screws from the recessed
bits of the Mac. If you want a longer handle - cut the
eraser end off the pencil and attach another pen
barrel.
As stupid as this sounds, it actually works.
To get the case apart after all the screws are out -
first make sure all the screws are out. (There is one
behind the battery door on the Mac/512/Plus). I always
just gently banged on the case near the seam with the
heel of my hand, and used my fingers to pull the case
apart there. It's not hard, and most of the time, it
will come off easily - especially if the computer has
been taken apart before. I never needed a case
cracker.
-Ian