I once tried sanding but the finish wasn't all that good and the monitor yellowed again within a year. Painting might work better.

The CRT is dangerous, yes, but discharging it is really easy. Take a flathead screwdriver, and an alligator clip, and attach one end to the screwdriver, and the other end to the "ears" of the CRT (which are connected to the grounding circuit in like 99 percent of CRTs). Slide it under the suction cup until you hear a POP and/or see an arc. If you don't, it might have already been discharged (most newer CRTs have bleeder resistors), but kinda wiggle it around regardless to make sure it's fully empty of any current. Now, the CRT is discharged and fully safe to touch anywhere to remove it. 😀

As for caps on the board, you can discharge them by shorting, but it's easier to just grip it away from their leads.

As for whitening the case, sanding or painting it may ruin it. I'm personally not a fan of retrobriting/whitening things, and I really only do it if the thing is seriously nasty yellow, but I understand if someone else wants their plastics to look nice; so, I would suggest trying to retrobrite it first before trying anything that could damage it further.

I'd just disassemble the thing and bleach plastic with hydrogen peroxide. Disassembly of a CRT is nor dangerous (if you leave it powered off long enough to discharge/discharge tube itself manually) nor difficult, just make right tools if it has internal clips. Sanding or painting would ruin it irreversibly imho.

I say if you expect decent results you can't avoid disassembling the monitor, either for retrobrite, painting, or even a simple thorough cleaning. Way too many nooks and crannies, vent holes, button/knob holes, and with CRTs being high voltage devices they are excellent at electrostatically attracting the nastiest kinds of dust, not to mention the heat they generate while operating accelerates degradation of the plastic (leading to yellowing and brittleness).
I've done the retrobrite treatment to one of my monitors and I'm quite pleased with how it turned out. 😀

BLockOUT wrote:

also taking the tube out of the front plastic seems very difficult.

Almost all monitors and TVs have a easy CRT mount. You need to disconnect all wires, then unscrew 4 screws at CRT "ears" and remove the CRT. But the first steps are to wait at least 5 mins from AC disconnection and to discharge anode of the CRT (using a screwdriver and a wire with two alligators or simply strapped to the screwdriver and the CRT ground, as said previously by cj_reha).

The tube should be kept shorted, they will redevelop a pretty nasty charge due to dielectric absorption aswell as just physical handling, they store static electricity pretty well.
The most dangerous part is the mains reservoir capacitor, the biggest cap there is. That one is able to kill you and will have to be discharged before you can safely handle the board. Disconnecting the plug while the monitor is turned on helps to make the process faster if you are going to wait it out rather than discharge it manually. I don't recommend shorting that cap, it will weld whatever was used to short it. I use a 150ohm 2W resistor that's been insulated for that purpose, no loud crack either ~