Mr

[butterfield]

How do you replace the bezel on a Rolex Explorer II ? 

Does it snap on and off?

Thank you.

[Tudor]

The bezels need to be removed with a tool. It must come straight up to avoid damage and it is a friction fit. 
 

You may get lucky with a razor blade to start it and then a case knife to get it the rest of the way but it should be raised from two sides at least (better four) to keep it straight. 

[jdm]

Four bladed bezel tool below.

https://www.aliexpress.com/item/10000014396096.html

I don't know about Rolex but other wise manufactures makes the inner bezel an hair smaller than the case opening so it can pressed out with the proper dies.

 

 

[Tudor]

That's similar to what I have. But I removed the blades and lapped and polished the top surfaces so there is less chance of scratching the mid case.

With rolex/tudor, plastic crystals press over the rehaut, and the crystal retainer (or bezel, on fixed bezels) presses over the crystal OD.

On newer watches, with sapphire crystals, the crystal sits on top of the rehaut, a plastic gasket fits around the bottom edge of the crystal and the OD of the rehaut, and then the retainer/bezel presses over the plastic gasket.

In both cases, then the bezel ring (with insert on plastic crystal models) snaps over the crystal retainer. On sapphire models, there is a click sprain that has to go into the crystal retainer slot and then the bezel presses into the spring and then down onto the retainer. There is a thin metal washer between them as well.

Once it's all together, and spinning/clicking properly, the insert can be pressed in, with the triangle aligned at 12:00. On the plastic crystal ones, the insert should be pressed in before the bezel ring is pressed on to avoid damage. 

Although there are exploded diagrams available on the web, getting the click spring in there is not detailed, and these things are easily lost (and overpriced).