You don't. You can only hope that a) future people won't revive you unless they're somewhat confident it'll leave you better off than you were when frozen, and b) worst comes to worst, they can still euthanize you.
Cryonics is ultimately a bet on future technology and future humanity.
Future people will use the frozen as a resource. I would buy a 2139-October call option on 100-frozen-hopefuls ... that's when I estimate techniques for revival will be viable and when legal hurdles to mass exploitation will be overcome. In 120 years nobody will care about your intentions in being frozen.
> I would buy a 2139-October call option on 100-frozen-hopefuls.
Unless you live inordinately long, you'll only be in a position to benefit from that if you are wrong about it being a worthwhile investment. (But right about the technological enablers—just wrong on the socio/legal issues.)
Cryonics is ultimately a bet on future technology and future humanity.