I just got an aftermarket metal backing for my iPhone, but I can't figure out what size torx screwdriver to use on the iPhone. Mine doesn't have the phillips, so I've been looking everywhere for a torx size but can't find one. I have a torx set which has T4-T10 and none of those fit .. I really don't think Lowe's or Home Depot sales anything smaller than a T4 which I already have. Can anyone point me in the right direction? Thanks