If this "body clip" is the same word used for a "blanket clip" then these are extremely easy to do! All you need, is a clipper and a bit of chalk and an on hand helper to help with tricky places. It is advisable to wash the horse before clipping to remove excess dirt but make sure he is TOTALLY dry before going near him with the clippers. Also a good bath afterwards takes away scurf and makes the clipped coat easy to moult . Trace the clip you want with a piece of chalk, and just follow the lines this is totally easy to do! But I would advise you NOT to clip legs or head as fur there is for protection, also have a helper to help you clip behind horses legs, round the stifle etc.......
Good Luck!