Just a few random searches.

how do i get a song from play music to music on htc

You pretty much don’t. As least not in any simple way that I know of right now.

clear partition cache m7

Have written about this several times, you have a guide about it HERE.

howto enable on body lock htc one m7

Have written about that HERE.

htc one update no face recognition

Yes, it’s there but under a new place and under a new name (trusted face). You have more info about it HERE.