I would use the microwave.

Ok, I'll cancel the crockpot idea. Guess what, I've only ever used microwave to re-heat coffee, make popcorn & eggs. Any idea how to re-heat the turkey covered?, how long. Just today tried re-heating cooked bacon. Think maybe I made bacon jerky. LOL.

I use my convection oven to re-heat meat because if you're not careful, the microwave will dry it out.

Is the turkey thawed or frozen? Best to thaw in the fridge (just like a raw bird) cut into serving portions and reheat. If reheating in the crock pot, add canned broth which can be made into gravy.
Not a good idea to put frozen in the crock pot.

you can reheat it any way but make sure the temerature goes above 160 degrees to make sure it is safe

Not understanding the comments about re-heating to a safe temperature? Am I the only one that eats cold turkey?

you can eat it cold but if you want to reheat it it has to reach 165 if it doesnt you would not kill bacteria that can cause illness

You can but I would take the meat off of the bone or at least make sure it's in pieces. I'd also place some turkey or chicken broth in it to give it moistue while it reheats. If it's thawed out you can also put it in a dish w/a very small amount of water or juice; cover it well with plastic wrap and microwave it; do it in increments waiting a few minutes in between each so the the heat distributs in the turkey and this way it won't dry out. Cooking and quilting are my two favorite things to do when I'm not at work.