Or there is this 3 week respawn thing where if your stuck in a situation and you can't get out for three weeks, they will kill your character after 3 weeks.
As others have said, either fly into a sun or have your faction execute you. After that there is a three-week wait before you can log back in and use the 'create new character' link. This is to discourage players from killing off their characters every time they decide to try something else, as well as to account for future combat delays. However, that's your only choice if you want to switch to something else.