Trunk Floor help

I am in the process of replacing my trunk floor, ext, and lower quarters. My question is all have been removed and my tail light panel is still in place, I am going to replace the tail panel also. Can/Should I do the trunk stuff first or all at once? If I remove the tail panel should I weld in a brace for support and so everything stays where it should be. First time doing this, using AMD, and everything has gone good so far but then taking stuff apart is the easy part!
Thanks in advance.
Author: Cupracer