[R-390] R390 ( non A ) crystal oven instructions

[K3PID]

OK, I give up! I need to replace Y404 and Y408. I have the manuals TM-11-5820-357-35 and the TM-11-5820-357-20. I have removed the Crystal-Oscillator Subchassis per section 60 of the manual and I’ve removed the cover of the oven BUT I can’t find any instructions for opening the oven to replace the crystals..... As usual, any help will be appreciated....

Ron K3PID