Tektronix 067-0532-10 Calibration Fixture Manual page 53

Maintenance
To remove the rf shield cover proceed as follows:
a. Unscrew the two captive No. 10-32 Phillips-head screws on
opposite sides of the shield cover. Unscrew several turns
at a time, alternating between screws.
The positions of parts in the rf section are critical. Do not move
stall the new one in the same position, orientation, with the same
of silver-bearing grease to the contact surface on the inductance
ring of LCl.