Sure he does. All he has to do is say that he's lost confidence in Ryan and his deputies, that they are jeopardizing his agenda. He can then call on House Republicans to find new leadership. His bully pulpit is a strong one should he choose to use it and that includes turning it on Congress. Consider if he did that AND address his supporters, calling on them to contact their representatives to demand new leadership. Ryan would be gone in minutes.
Unfortunately Ryan is friends with Rinse, so Trump won't get good advice on getting rid of Ryan and his deputies.