Removing that pearl plug usually isn't difficult at all. First, check to see if it is a screw or a bolt in the hole. (Bolts are easyest, screws are a bit more fiddley.) Stick your hand inside and see if you can find the nut on the end of the bolt or the sharp, pointy end of a screw.

If it's a bolt, find a socket that fits, then remove the nut. Now, take a coin in you hand and reach into the instrument. Place the coin on the bolt end and give a sharp, hard push on the bolt end. This almost always pops the pearl plug out along with the bolt.

If it turns out to be a screw, you'll have to break the pearl away from the top and replace it later. Most luthiers can supply you with the proper replacement pearl dot for a nominal charge.