We had two great fellows, Dan and Julio, for close to 20 years; they were delightful gentlemen whose personalities outweighed those of many humans that we've known. Lost them both about four years ago and their absences are still noted.
We believe that his hooves are not in critical need of trimming, but could use a bit off to make him most comfortable.
Hope his easy disposition lends him to behave for a farrier's attention (some farriers do not enjoy dealing with burros), as some of them just hate to have their feet handled and are a bit fiesty.

Shouldn't take more than 15-20 minutes...if Jack approves. You could help by standing at his head and offering him an alfalfa biscuit or two during the trimming; that would make Jack a happy camper.