If you can put a spanner on a nut without burring it up and can tell if the bolts are imperial and not metric then you can rebuild a Holden commercial vehicle. They are easy if you take your time and get on here and ask a question if you have any dramas. Use the book like razsandman says. Problems with heater controlls are probably the hardest to work on to start with as it usually means a bit of dash disasembly. Just remember that if this farmer can do it so can you.