I'd get a pilots license as fast as possible, steal a passenger plane and fly it into jagex hq (jumping out to safety beforehand obviously). Then i'd come on here and lol at all the people that they their bots arent working and I could truly say 'Gf jagex'.
It's really hard to answer a question like this, when you have a pretty vague idea of how'd you feel being in that situation.. at least for me that's the case. Anyhow, I'd imagine myself probably want to travel and experience new things and spend time with my loved ones.
Do a bunch of illegal shit, eventually get caught, and get locked up.. And on the day you're supposed to die, your doctor calls you and tells you that he gave you the wrong evaluation; and you just had a minor gas problem. Bahaha, that would suck ass.