Audio Research D400 mk2 amp

Has anyone had to replaced (them selves) the 4 can caps under the main flat board in the front of amp?
Do you just loosen solder on the flat top and unscrew and the caps that drop down? looks like screws under the solder.
Do they twist or snap into place from the bottom, etc. without unsoldering ?
I'm capable of doing it but was just asking.

what happened was after moving amp around when turning off/on at times it would arc under the cap board.
just touching the top with lead and pushing for voltage check would zap too.

After i soldered over all top areas where the screws were no more arcing with on/off.
So maybe just bad joints on flat top area after jolting amp around. (??)

I checked main voltage which should be 65 volts at around 120 mains.
I get 64.8-65.2 on plus side.
64.5-64.7 on minus side.
No bulging or leaks that i can see.
Maybe voltages are within range..
No difference in sound. 
always kept on all the time unless away for long.

Your thoughts Please..

thanks George