We replaced the dry rotted sole on our 38 recently. Decided to put bamboo down instead of teak and holly. Its more durable,more rigid, very renewable, lightens up the cabin and was cheaper than t/h ply.
I used a small flat screwdriver blade to remove the bungs. Tap it in with the grain at a slight angle and pry up the pieces. I like the drywall screw idea, gotta take one down to the boat so I will have it around. Also a little hint to get the screws out, buy yourself a few new phillips bits for your screwgun. Get at least one long one and use a hammer to tap it firmly into the screw-head before you try to back it out. The heads will have glue in them and the bit wont seat properly. Once you spin the bit on the head, its not going to come out until you can grab it with the vice grips. My floor was so rotted I could just pull it up by hand and twist the screws out with the pliers. Some broke off but i just ground them flat with the gelcoat.
Also dont be shocked when you see under the floors....... Simple green, hot water and a stiff brush cleaned mine up pretty good. I brushed white gelcoat on the unfinished tabbing to finish them off a little better.
I'll be happy to post pics of the bamboo floor if you want to see.....
Ben