i'm no expert, but here's my 2 cents.
it's ok to bake ahead, but i wouldn't slice it until sunday, when you're ready to reheat it. it will dry out a little if sliced too early. after the ham has cooled enough to handle, wrap it in plastic wrap, then foil, and put it on a plate in the fridge.
to reheat, i would put the slices in a pot or deep skillet with just a little water, cover and reheat on medium low. don't use too much water, tho. you're not braising it, just kinda adding a tiny bit of moisture to help conduct heat and keep the ham from browning.
in nomine patri, et fili, et spiritus sancti.
beidh ar la linn.
wisdom is often in short supply within ones' ego.