We have an older home and the toilet on the first floor was leaking at the bolts that mount the toilet to the tank. Upon further investigation I realized that one of the bolts had broken free from the tank...the toilet is from 1955 and the bolts are actually grouted into place, no O-rings. I want to use the same tank as it matches the other fixtures in the room but am uncertain how to remove the grout from inside the tank properly so I may use a new boltsd and o-rings to seal the tank. Any help appreciated as I'm afraid I'll crack the porcelaine if I do it improperly.