What is the best way to replace leaking shower pan in tile shower on a concrete slab floor?

What is the best way to replace leaking shower pan in tile shower on a concrete slab floor?

The operating word here is "replace". All the tile and mortar will have to come out up to the highest poimt in the pan wall and the shower drain flange will have to be unbolted and the pan removed. You may now clean the area and pab the shower. If you need instructions on how to pan your shower contact me on the Plumbing Page. Good luck and thank you for rating my answer. Tom

Do you have any idea where the leak actually is? A custome pan with a menbrane can leak but you got to get passed the tile, grout and thinset to actually leak. Could this be a drain leak? This isn't a fiber glass pan is it?

Its not a fiberglass shower pan. It was built in the 60's.