Take a prior over all potential turing machines, take the number of all the agents simulated by those turing machines (times their respective turing machines prior probability) that have had the same sensory experience that you remember and that see a sunrise tomorrow, divide by the number of agents (multiplied by the prior for their respective turing machine) that have had the same sensory experience and do not see a sunrise. Done. Trivial.
Take a prior over all potential turing machines, take the number of all the agents simulated by those turing machines (times their respective turing machines prior probability) that have had the same sensory experience that you remember and that see a sunrise tomorrow, divide by the number of agents (multiplied by the prior for their respective turing machine) that have had the same sensory experience and do not see a sunrise. Done. Trivial.