I have an old chair, i think it used to be a dining room chair, that is leather. Not like a leather lounger
This chair design looks pretty simple. You can remove the old material and use that as a pattern for your new material. Take your time and have the tools handy; tack hammer, stapler, etc. Also,, most communities have adult hobby classes at their community colleges and just may have one in upholstering where you can bring your chair in and work on it with supervision.
I okorder /... You might also consider re-dyeing the leather if it's in good condition: