High guys, I'm attempting to remodel a small bathroom and this is my first attempt at something like this so I want to run my game plan by people with experience to get some feedback and tips.

I am keeping the layout of the room the same, so I do not anticipate having to move any plumbing fixtures. The house is 1980 construction, and everything in the bathroom seems to be original to the house. House is single story on a slab.

My biggest questions are with the tub replacement. I currently have a 30"x60" tub/shower combo. It has cracks in the bottom (seems to be made out of fiberglass?) I am assuming there is sheetrock behind the shower walls? I can not fit a single piece replacement unit through the door, and the mrs does not like the idea of a 3 or 5 piece unit being installed so my plan is to buy a tub and tile the walls for use as a shower. Here is my game plan, please tell me where steps are missing or if there are options that may be better or easier than what I have listed.

1) remove old shower. (looks like i'll be cutting this into several pieces to get it out of the door - reciprocating saw / sawzall)

2) remove any drywall behind shower. - plan is to score drywall at edge of tub prior to removal of shower. I do not know if there is a stud at the edge of the tub, I will add one if there is not to allow for installation of the backerboard later.

3) replace any plumbing necassary for installation of new shower head

4) install tub

5) install plastic membrane over studs ( is this needed? I have read conflicting opinions.) I am planning on using plastic sheeting stapled to the studs with it ending at the lip of the tub.

6) install backerboard - what is my best option? seems like the concrete backerboard is the most readily available choice. does this need to start at the top lip of the tub? or should it extend floor to ceiling behind the tub? if floor to ceiling, i guess step 4 will come down to below this step.

7) tape joints of backer board - mud over joints

8) install tile - (12x12) using thinset (is mastic a viable choice for this size tile?) 1/8" spacing between tiles for grout. How large should the gap be at the wall / ceiling edges? does this gap get silicone caulking instead of grout?

9) seal tile / grout - how long should I wait to do this?

As I get to some of these steps I am sure I will have more in depth questions but how does my overall plan stack up? am i missing anything?