Mark Levinson 5302 top cover

Good...

Glad you figured it out.

Come to think of it Kim did mention "HEX", but I wrongly assumed that it was something she did to Mark. 

DeKay

Actually you need to remove 4 hex screws , they are 2nd screw located on each top corners of heatsinks. If you enlarge the photos of top cover removed there are 4 white dots on each corners where the hex screws are attached to the top covers which has 4 small brackets.  Call the Mark Levinson support centers but wouldn't give me answer due to safety reasons :::::::::::??????  took some time to figure out.  Thanks 

I cheated (called Kim Cattrall for the answer).

DeKay

Ha! I was right. :)

Looks like the top piece (between the heatsinks) slides towards the back.

DeKay

I have no personal experience, but is it possible the top is a cosmetic, slide-off cover?  Otherwise, look underneath the amp for access clues.