All you need is the biggest flat head screw driver you can find, and grind a notch into it for spring removal.
That's what I use, except I used a medium size pry bar. There is a for real tool you can buy.
The other way to do it is to use an adjustable wrench or pry bar to spread the end with the rollers (cam end). Then you can pop out the rollers and the shoes will close far enough you can take the spring out by hand.
Depending on the slack adjuster, it could be a 7/16, 9/16, or 5/16 square.
I suppose you really should replace the anchor pin bushings every time, but I usually just leave them unless they are in bad shape. Put some anti-sieze on the new anchor pins and they will last a long time.
If you need to replace the cams or cam bushings, that's a whole lot more involved job. Most of them will not come out without removing the hub.
BTW, if the truck has "Dayton" style wheels, where the rims don't have centers and hubs have 5 or 6 spokes, that brake job is a lot more difficult. Those axles have inboard drums and you have to break down the hub bearings to do a brake job.
