I'm installing a new tub ( an Americast Cambridge left-hand drain apron tub, nothing fancy) and bought this drain for it : http://www.americanstandard-us.com/b...ep-soak-drain/

The drain is ABS.

The existing plumbing has a brass P-Trap which I can access from the 1st floor.

My question is how to connect these two? Should I unsweat/remove the Brass Trap and put in a different one? Can I simply tighten the new ABS Drain down to the Brass Trap using the connection ring it came with and some teflon tape on the threads? Will this leak or crack once hot water hits it? Should I use a Fernco coupling?

I'm a bit lost as to what to do to avoid leaks. Once this is connected I'll be closing up the access and it'll be a major deal if it leaks on me.

Thanks in advance.