Being an all aluminum, uni-body device, the HTC One is extremely, extremely difficult to repair basically anything.
Most phone and mobile repair professionals I know or have come across, won't touch the HTC One.
Check out iFixit.com and their teardown manual for the HTC One. It's ridiculous lol... They gave it a 1 out of 10 (1 being the worst/hardest) in terms of repairability. As Gator mentioned above, call HTC.