You can just wait for the leaves to fall off which they will do soon, or you can clip them off ( do not rip them off, leave a small piece of the stem on the plant which will fall off by itself in a few days).
Your plumeria will soon go dormant. It depends on the variety, I have some plumeria that have already lost all their leaves and others are still going strong. I am also in South Florida.
In the early spring, please fertilize with a well-balanced fertilizer to make a strong plant.
Good luck.
