I'm pretty positive that HTC didn't fix mine but sent me a replacement phone as the imei number changed and the damage to the ally body 2 deep scratches had magically gone.
I broke my screen a week into ownership. A quick Google brought up ifixits teardown and for self repair the HTC one gets 1 out of 10 ......it's not self repairable. Had to send it to HTC
http://www.ifixit.com/Teardown/HTC+One+Teardown/13494/1