If it is more than a hydraulic hose/fitting then the cylinder must be removed for proper repair. It has a packing at the rod end but I don't believe it has anything other than a welded base. If there really is a leak at the base then it may require a much more in depth repair such as replacement of the barrel. After you thoroughly clean the cylinder you may discover that it is oil running down from the rod end and making it appear it's leaking at the bottom. You don't say it but it is assumed that this is an underbody hoist and not a front mounted telescopic. Precaution must be taken at every turn to adequately block the body before attempting removal. That shouldn't have to be stated but there it is. Better yet let a pro do it.
I know all the body upfitters in OR so if you need a reference I can help you.

1953 Chevy 5-window 3100
In the Stovebolt Gallery
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Dave
Engine & Driveline Moderator

If you can't make seventy by an easy road, don't go. ~~ Mark Twain