you can find Allen Hex Wrenches at Lowe's, home depot, ace or pretty much any hardware/department store. Most important, you have to know that you'll be voiding your warranty if you try this. it would probably be better to just take it to a VZW store and have them do it for you

 

Its not a hex its a torx driver not sure of the size i think its a #5 torx.

 

hex can be used as a substitute.. only problem is its not a reliable tool because the head of the screw may strip

 

you can get torx at any hardware store dont use hex!

 

good luck finding a how to. I have seen a couple posts like this and it seems they just drift off into open seas. I searched my damnedest for a video or even something with a couple of photographs and haven't found anything. I am considering doing the same thing but I am pretty sure it will void my warranty. If you feel like smashing completely to pieces for insurance I won't hold it against you.

 

It will absolutely void your warranty and is easily detectable detectable. Just thought I'd let you know the risk if something were to go wrong in the process of replacing or if something were to happen afterwords. Now if you have insurance and don't mind committing insurance fraud, you can always just smash or "lose" the phone and file a claim.

 

Those four screws are are Torx screws. You are braver than I am but I guess it's hosed anyway. Where did you ever find a replacement screen?

 

The HTC Eris and HTC Hero are extremely similar in build

Take a look at this HTC Hero disassemble video and taking apart the Eris should be pretty close.

Good Luck!

YouTube - How to clean the dust inside HTC Hero screen