Quoted from KeithinMI:/nod. On Stern's it's definitely a one-person job for the mirror blades. IF you have the right tools. On both a tspp and a lotr, I was able to do it alone, quite safely and cautiously (save the TSPP couch) using three c-clamps to hold the mirror blade in place after it was placed properly (and after I had to remove those silly wooden purposeless blocks on either side). Power unplugged, playfield up all the way and slid over to the opposite side of what I was doing. On the STLE to put in the sidewall art, it was a 2 person job, as I needed my son to balance the playfield upon the rails while I put the art on the sidewall. I would even call the sidewall art a 3 person job because having someone on the front AND back of the art would make it easier to get it installed correctly.
I actually cut out on both sides to account for the wooden blocks. What a pain that was!