Moulded shower base over exisiting shower base

Is there any place to get information on how to install a moulded shower base over an existing tiled shower base?
What I'm concerned with is the connection of the shower drain to the moulded base - does it call for an adapter/extension?
Your vast insight in this matter will be greatly appreciated.
Thanks all in advance

Not sure how you'd attach the drain...plus, I'd worry about water getting behind the edges of the pan that flowed down the walls. I'd worry caulk wouldn't be reliable. My unprofessional opinion.

I agree with Jim. You would have at best a jackknife job that would require gobs of what my dad referred to as, "1/2" putty". Take the time to remove the tile and do it right.

Been there - thought about that!! You're asking for nothing but trouble down the road. A small sledge hammer and chisel will remove the old shower floor quickly and efficiently - and you can do it right from there...Good luck!