Usually you just twist the tube to remove it. There are other things that can be wrong if the tube fails to light. If it is an older light it might have a small silver cylinder at one end of the bulb. I think it is called a starter. The starter also twists to come out and could be bad. The other possibility is the ballast. The ballast is inside the fixture and, if it is bad, it might be cheaper to replace the fixture..
