Here;'s how to match up the hole perfectly.
Take off back case
Plase masking tape on phone so that it covers the reset button and the long edge matches up with the edge of the case where the back cover meets the rest of the phone, and where the top of the the tape goes to the bottom of the vol buttons.
Poke a hole/use a sharpie where the reset button is.
Pull off tape carefully
Put back cover back on.
Take the tape and put it back on the phone, matching the edge to where the back cover meets the phone and the end of the tape is right at the bottom of the vol buttons. Basically, exactly where the tape was when the cover was off.
You now a have a perfect guide to drill right on top of the reset button.
Or yo ucould just go to a T-Mobile store and swipe a back cover