[R-390] How to remove RF module?

[ALLEN MARTIN]

Brought home a 390a a couple of days ago and after putting a few tubes in it and doing a few other things i have good audio out and can change filter widths but no signals coming through. touchings the grids of the rf amp tubes isn't doing anything either. No signals or calibrator on any band so far. I guess I will get out my ganeral coverage receiver and see if I can hear the crystal oscillator or the PTO. I did download the Y2K manual so have some good reference material.I don't see how the rf module comes out. I do see a couple of screws toward the back but not the others...yet. 

Open to suggestions. I have another complete non working one too... 

Tnx! 
Marty 
KL7AM