It is very easy. You don't even have to remove th ewheels depending on the axle that you plan on swapping over. I've done plenty of D44 fronts where I only removed the wheels once, the first time I did a swap.

 

Well by your user name I would assume that you have a D44 front in your truck. Do you have automatic locking hubs now?

If so, I would install Warn's premium hubs. They are very easi to use and install. Plus they add some strength to the front end.

 

Cheap? used auto parts store (a.k.a. salvage yard) or a junk yard. I know a rebuilt unit will go for a few hundred ($400+).