Step 1. Remove the existing cap and detach chain at filler neck.
Step 2. Remove the plastic sleeve.
Step 3. Fit the Diesel Guard unit into the filler neck and turn and lock in place.
Step 4. Finger tighten the bolts.
Step 5. Tighten the bolts evenly with a socket spanner (8mm) one turn at a time until the heads break off.
Step 6. Re-attach the chain and cap.