Actualy you dont need to remove the crystal, but you have to remove the movement with the dial attached from your watch, a generic opening tool for rolex sub wil work to open the back case of your watch, and apropriate screw divers to remove the movement pushers that keep the movement in place,. I'm shure you can see how to do it on several posts here so do some research.Dont forget that to the movement to get out from the case youl have to get the stem/crown out of the movement. The markers on the noob dial are secured by a litlle pin on the back of the marker that fitts on a litle hole on the dial. most secure way is to put a very very litlle grop of shooe glue (contact glue) that will take some time to get dry and once it is, it will be kind of rubber texture so its ease to remove. You can do this with a nedlle or o tooth pick , and than put the marker on its place. This glue is the same i use to glue the bezel inserts and it's secure but allways allow me to get them out of the bezel easely with no damage at all. When dealing with the dial you may put some finger prints on it and it may collect some dust, the best way to clean it than will be to use a product called Rodico, but i stongly recomend you to use rubber gloves to avoid getting the dial realy dirty.