hey-
start by getting spare stock b'fields at your local wreaking yard, should be around $40-50 bucks apiece. replace one in your drive way so you know what's involved, ie:
54mm socket, brass punch to remove cone washers, 2 lbs fresh grease, two rolls of paper towels, torque wrench, snap ring pliers, brake parts cleaner, etc. shouldn't take over an hour.
if you find your bustin'um frequently, start saving for an alternative. Kongs4x4 is using cv unlimited's b'fields on his truck w/ good results so far. they are the same as a Marfield, but have a better warrenty.
later