For your probability, you should recall that a conditional probability P(A | B) = P(A and B)/P(B) so if you can find P(A and B) you can get the conditional probability.
If you are in the rejection region, the probability is given by alpha (the alpha value) and this is when X <= 1 or X >=9.
Now the likelihood ratio is L(theta_est)/L(theta_max) so you will need to convert this back to a probability for the cutoff.
Recall that the likelihood is between 0 and 1 always and there is a connection between the relative likelihood and the probability.
Hint: What is the connection between relative log-likelihood and the p-values corresponding to this value?