Disconnect the water and drain lines. There is a special long handle wrench that really helps. I found mine in a hardware store. Take off the trim insert nosing on top and the trim along the lower edge. drill out the rivets with a 1/8" drill. If that is too small use a 9/32". A standard rivet gun with 1/8" pop rivets will work. I would try 5/8" length rivets. While you are at it check you tambour for any needed repairs.
Are u replacing it with a new unit? Where did you get a replacement and how mucha?
Sail on silver girl. Sail on by. Your time has come to shine.