bi folding pantry door to frosted single door?
I replaced several bi-fold doors with pre-hung and for all but one I removed the drywall down to the rough 2x4 framing. For one thing this allowed standard doors to fit.

For one narrow closet of odd size I got a custom pre-hung door and did not remove drywall. I didn't remove the drywall because the interior dry wall face extended all the way out the outside. There must be a name for this kind of closet.