In the documentation that comes with a Rolex watch, owners are encouraged to take their Rolexes to authorised service centres for all service, rather than attempting repairs themselves. With the right tools, though, you can safely remove the back of the watch in just a few minutes. Once the back is removed, however, the sensitive parts and instruments inside become immediately more vulnerable, and you'll want to be sure that you know exactly what you're doing from that point forward.
Purchase a Jaxa wrench and watch case holder anywhere watch repair products are sold (see Resources). These are specialised tools that are only used in watchmaking and repair. A Jaxa wrench is a special style of wrench that can be used to open most watch styles, including Rolexes. A watch case holder looks similar to a small vice clamp and is a system used to safely stabilise a watch while you remove the back.
Loosen all of the screws around the cradle of the case holder so that you can easily slip the watch case inside, then loosen the screws controlling the clamp on the bottom.
Slide the main clamp of the watch case holder over the edge of a work table or some other stable surface, then tighten down the screws.
Put the Rolex watch case in the holder face down, then tighten the screws around the cradle until the watch is firmly held in place.
Examine your Jaxa wrench bits and compare them one at a time to the notches on the back of your Rolex watch case. Rolex uses different notch styles on different models, but all of the bits are distinctly different.
Attach the proper bits to the Jaxa wrench. You'll need to attach three identical bits by pushing them all the way down onto the three bit mounts protruding from the flat side of the wrench.
Put the Jaxa wrench down gently on the back of the Rolex and line up the bits with the notches on the watch case. Apply some downward pressure and gradually turn the case back to the left. It will be hard at first, but will loosen significantly after the first half-turn. Continue turning the wrench until the case back becomes loose enough to finish by hand, or until it pops off the watch case.
Opening the case back yourself may void the warranty on your Rolex. The safest way to service a Rolex, which is one of the most expensive watch brands, is to send it out to a Rolex certified repair technician.