What parts are you wanting to redo and why exactly? Like are the cushions worn out and cracked?
A picture would be very helpful.
What is it you want to do? Is it old or newer? Photo really would help.
Here are two tutorials:
My dad did this years ago!!! He painted the metal and then got the actual leather redone. You can take it to someone or if it's intact you can find paint that can work on leather!