Hi Headlap, you can probably clean the switch without removing the headblock but it's very easy to remove it. If you look at the block, there are black headed screws in groups of 3. These are the adjustment screws for the heads. There are 3 silver allen head screws. These are the ones you need to remove to remove the block. There are other silver headed screws that are for the guides but they aren't allens. You can also look at the guides and figure out which ones these are. After removing those screws, the headblock pulls straight off. Sometimes you have to rock it gently since it is held in place by a multi-pin connector that connects the block to the electronics of the strobe, and 4 heads. Once you've removed the headblock, there's a black plastic shield held in by a single screw. After removing the shield look for the back of the switch. There are little openings in the back of the switch that will allow you to spray some DeOxit. I use D5 spray (lasts forever). Just give the switch a quick squirt and work the switch over and over. Be careful not to get it on the heads or guides and while you have the headblock off, give them all a good cleaning since it's the only time you can see the left channel side of the heads (farthest away from the deck plate). If you find a lot of oxide build-up on this normally hidden side of the heads, you need use more of an angle when you normally clean them (when the headblock is still installed) to keep the oxide from building up. The installation is the reverse with not special tricks other than just tighten the screws till tight. They don't need to be torqued down! If the problem persists after doing this cleaning twice, you'll probably need to disassemble the switch and clean the contacts directly.
BTW It's a good idea to have a service manual and it has good illustrations of the headblock and all the screws.
Having a great time at VSAC. I wish all you guys were here!