using a filter needle is certainly not a bad idea. as for the amps I usually score around the inner lip w/ a pair of scissors, the skinniest part of the amp, take a pen cap and put it on the top of the amp a little above the score you just made and just snap it off. It may not snap off where you want it to so when you are holding the pen cap try dif. angles from where you are trying to snap it off of, amps usually like to snap off in a particular spot as it doesn't really take much force to break them. also sometimes the glass will get stuck in the top of the cap so i just squeeze the hell out it over a trash can to break the glass out of there. hope that helps you out.