removing a dell cd-rw?

you can't it is write-protected

There is no way to answer the question with exact specifics without knowing the type and model ie desktop/laptop and model. However in general for a desktop computer you turn off the machine then disconnect the power source and all cables... remove the side covers . inside the case locate the drive to be removed , disconnect the power, data and audio connectors , then remove the mounting screws typically there are 4, 2 on either side. Once the screws are out slide the drive out toward the front of the case and once its clear you are done. On Laptop models ther are a variety of mounting methods, most models use a slide latch on the bottom of the case, with power off simply slide the latch whichever way is indicated for release (usually to the left) and slide the drive free of the case.