Finally got the new tank. Thought I would share the replacement sequence, which I wish I would have had going into this.
I'll share the problem first.
The toilet and shower tray needs to be removed to access the tank. Here is where I started. I removed the hard walls to get better access.
Here the toilet is removed. I had to cut the vent plumbing to unscrew it from the fittings. Instead of buying all new vent plumbing I used a coupler to fuse it back together when re-assembling. Access to the shower drain plumbing (lower right) is underneath after removing a protective cover. This must be removed to get the shower tray out.
I removed the toilet flange with my DIY tool.
Here I have removed the shower tray. This part sucked. The screws are easy but all that caulking is tough to break loose. I had to remove the towel bar and soap tray to get the shower tray out but no big deal. The new tank is in.
From here it's just reversing the process. This entire process took about 4 hours, including replacing the waste valve and all associated plumbing. Total cost about $300.
I hope this is helpful to someone