Silcone caulk was placed around the top of the bathtub after we installed ceramic tile. The silicone is catching water in the grout lines and mildew is growing. I have tried to clean it but cannot get it all. I would like to remove the silicone caulk, clean area and replace with different caulk (silicone was not easy to work with). How do I remove the caulk and what is a good caulk to replace it with. Thanks for the help.