Cross-Over pipe you will need - hosing, 2 barbs, pliers, file, hammer, vice, wood. 1. Cut the hosing to length with a pair of pliers. Hold it next to an existing cross-over to accuratly measure it. 2. Get two pieces of wood that will fit in your vice. the ones i use are about 30x70x100mm 3. Grab a file (or anything that will indent the wood) and make a triangular shaped impression down the middle of both pieces of your wood. This impression is the guide for the hosing which keeps it in place when tightening the vice and when the barb is being hit into it. 4. The blocks are finished. Put them in the vice with the hosing through the middle making sure there is just short of an inch of hosing sticking out of the top. 5. HARDEST BIT: now it's just a case of hitting the barb into the hosing. (the hitting part of the hammer should be softer than the barb you are hitting so it dosn't fold the barb in). Now repeat the process for the other side, i think i messed this up about three times ha hope this helps