I would have to disagree.
There are no traps involved with opening a BVM, at least as far as I have seen. It is literally as simple as taking out screws and removing flat metal panels, much like opening an old PC tower. The worst it got for me was that the back panel had a couple of wires running from the S-video connector to the main unit, and I had to be careful not to yank on them. Unlike consumer sets, BVMs are made to be easily opened for routine maintenance.
In consoles, capacitors often function only to filter signals. These are typically small, they have low-stress lives, and if something goes wrong with one of them, the worst you suffer is crackly sound or some oddity in your picture. In BVMs, however, there are many large, high-voltage capacitors that are directly involved with supplying power. Bear in mind, these TVs easily pull 20 times the wattage that is ever used in, say, a Turbo Duo. The big capacitors are under more stress, and when they fail, you run the risk of both damaging other components and spilling lots of corrosive electrolyte everywhere.
If you have never done it before, I would strongly suggest that you look at the capacitors on the power supply PCB and the deflection card PCB. The former is the one that the power cord connects to and is probably inside of a big metal case, while the latter is a big thing on the left side that electrically sits between all of the signal processing PCBs on the right and the tube itself (not to be confused with the board on top, which is the final RGB signal amp). Combined, there are probably two or three dozen high voltage caps on these. If nothing else, eyeball them for leakage and bulging, both at the top and the bottom of the cap. If any of them are starting to go, I would say to hell with it and replace any cap on the board where the voltage and microfarad ratings add up to more than 100. That, or just replace everything for peace of mind.
If there are no problems, you'll probably be done in 20 minutes, and you should be good to go for hundreds of hours of operation. The risk of damaging your BVM just by opening it is extremely low, while the chances of finding a problem are fairly good, and the advantages of fixing a problem before it becomes a crisis are great.