Conversation so far:
what was one of the laws that Selim III reformed?
Selim III introduced salutary reforms into the administration, especially in the fiscal department.
was there another law that Selim III reformed besides salutary reforms?
Selim III sought by well-considered plans to extend the spread of education.
were there any more laws that were reformed by Selim III besides salutary reforms and the spread of education?
Selim III profited by the respite to abolish the military tenure of fiefs

Question: how was the military reformed?
Self-contained rewrite: how was the military reformed by Selim III?