New Build. need advice for P/U install

[Diehlicious!]

I'm in the process of my first build, I'm calling it a 000Naught as it's drednaught in depth and 000 in shape. I'm about done with the top and bottom and wanting to install my p/u system, a JJB prestige 300. (I believe it's very similar to the K&K with 3 transducers.) As it is. I have my bridge plate down but don't have my bridge installed above. Wondering what's the best procedure to get the p/u installed before I nail it down and have to play with mirrors.

thanks in advance! Brian