Everything being proper, changing a barrel on a switch-barrel rifle is very easy. Pop one barrel off, clean any grime from the action, and screw in another.
Even if iron sights are involved, the task is not that tough. At one time I had a Remington at the Canadian Nationals with two barrels. One a 5.56, the other a 7.62. Between ranges I would change barrels, zero the sights for that barrel, and go to the next range with confidence. The main problem was in holding on to that rifle. An old friend from Windsor nabbed it in one caliber and I had to come home with an extra barrel and bolt.
A scoped rifle makes it real easy, especially when it is a so-called tube gun. The main advantage there is the ease of getting a good grasp on the barrel.