The clips are on the inside of the u-joint. Look under the ear on the back of the u-joint. You will see the clips. If I had the hubs off I'd do the same thing. Not only does it have the potenial to leave you stranded, but it can break off the ears of the shafts too. A piece of advice, Carry tools to pull hubs and pull the shaft before driving with a broken u-joint. It'll save you extra bucks. Make sure when you put the hub on to use anti seize. If not next time you pull it , it'll be another pain in the ass to get them off.
Though pulling shafts on the trail is a pain you won't be sorry you did it.