Remove old caulk with a utility knife or caulk remover
Clean the joint thoroughly with soap, water, and a mildew remover if needed
Dry the area completely
Tape both sides of the seam if desired for a cleaner line
Cut the caulk tube tip at a 45-degree angle
Puncture the inner seal of the tube
Load the tube into a caulk gun
Apply steady pressure and run a continuous bead along the seam
Smooth the bead with a caulk finishing tool or a damp finger
Remove painter’s tape before the caulk skins over
Let the caulk cure for the time listed on the label
Avoid using the tub until the caulk is fully cured