To take it off, seconds. But you also have to remove the caliper assembly for the disc break, and for transport you'd have to deal with that dangling. On the plus side you don't need to deal with navigating around or opening up rim breaks.
According to the manual, when you put it back on you're suppose to wipe off the spindle and regrease it, then torque to 113 in. lbs.
So to put it back on "by the books" you'd need a towel, grease, and a torque wrench.
Still only takes a few minutes though. I'm not sure how critical that stuff is - I defer to the more experienced leftyologists here for that.