Remove the Ceiling Tiles
Investigate how the ceiling tiles are attached. If they're glued directly on, it will take some extra effort to remove them. If they were attached to furring strips, the job will be easier. Use a utility knife to score the tiles, then a putty knife to loosen and pull loose a tile for inspection (Image 1). Fortunately, the tiles in this home were attached using furring strips.
Begin removing the tiles. First, remove the old crown molding, then use a pry bar or claw-hammer to pull the old tiles loose (Image 2). This goes faster with two people or more, working on ladders from various points of the room.
Use a pair of pliers to pull the old staples from the furring strips. Make sure the strips are left smooth. Anything left on them could create a bump in the drywall when it's installed.
Reinforce the furring strips by driving screws through them, and into the ceiling joists.