Usually, removing remotes is easy. Too easy. Ask me how I know. Typically, holding down the program button for too long will remove all remotes. Fortunately, adding remotes back in isn't all that hard. As flechero said, it is best to refer to the manual.
Just keep in mind something very important. Due to residential code, all garage doors have this red pull cord that disconnects the garage door from the motor, making it a piece of cake for anyone to open the door manually, usually with something like a wire clothes hanger. It is a common way for thieves to get into the garage. Unless you have a way to prevent easy tampering of the pull cord and corresponding lever, consider all contents of the garage insecure.