Any users here experienced at modding HTC phones?

[Megatomic]

Anyone here experienced with modifying HTC phones from vendor models to unlocked models? I have an AT&T One A9 that I'd like to make into an unlocked/retail One A9. I've found some info on XDA about how to do it but I feel a little uncomfortable. At one point I had CyanogenMod installed on it but it was not a good experience, audio and LTE sucked basically.

If any of you guys has a solid "guide" on how to do it would you mind sharing? I'd almost be willing to pay someone...