As Long As It’s Black: iPhone 4 Now Shipping With Anti-Tampering Torx Screws
appadvice.com
appadvice.com
There was also a... "cracker", or spreader, I seem to recall, to aid in getting the pieces of the case to separate. One inserted it into the narrow seam, which it then widened.
EDIT: The important part was to discharge the CRT, before you did so inadvertently.