I need a mini-y comp removed and a phantom installed. Anyone do this kind of work and guarantee not to screw it up. I don't want to ship off my upper. Thanks.

If you or someone you know has a drill press it's a pretty easy do it yourself job. Drill out the pins at 6 and 12 o' clock (take it slow and you'll do fine) unscrew the Y comp and slap on the Phantom. I thought we had a FFL/gunsmith from Hobbs that posted here but I can't recall his user name.

You're probably too far south for me (central NM), but if you aren't trying to save the mini-y comp, it should be fairly easy for anyone with a functioning brain to remove it  with a cut-off wheel without damaging the barrel.   I don't know how you're planning to attach the phantom so I won't comment on that.

I don't work on ARs for a living, but most anyone with a moderate amount of machining experience should be able to repair one.   They just aren't that complicated or difficult to work on, and the repair data is widely available.