What year truck do you have, as a Pre-73, this is not required to change out the 'switch', which is what I think you are trying to say you want to do.
If you have a post 9/72- you will need to remove the three screws that hold the pad on the center of the steering wheel(they come in from the back side of the wheel, really the front), then remove the nut on the steering shaft, and you may be able to pop the wheel off the shaft by striking the back side of the wheel with both hands, put the nut back on a little in case it pops off, so that it will not hit you.
I really do not think that you will be able get this apart without a puller, but you may. Otherwise, I would try renting a puller from an auto store, or just purchase one, and the two longer bolts that you will need to use. They are metric, 8mmx1.25 thread, 70mm long or so should be good.
Good luck!
-Steve