I used shoe polish. If bad will need to replace but usually cost more than what the tables are worth. I flipped a set of those that the leather had cigarette burns on them so I pulled off the leather. Sanded down the glue residue and decopaged sheet music in the insets and coated with polyeureathane. They sold very quickly.
What is wrong with the leather that needs to be re-done?
Is the leather worn down, ripped, or just dry?