1. Locate the lock position on the bottom sash window frame. Install horizontally or vertically on the top left corner or the top right corner of the bottom sash frame.
2. Hold the lock body in position and mark the position of the fixings screws and bolt hole.
3. Using a 2mm drill bit, drill pilot holes for the fixing screws.
4. With the window in the closed positon, use a 10mm drill bit to drill the bolt hole through both the front and rear sash frame.
5. Use the screws provided to screw the lock body in place.
6. Insert the bolt to test for smooth operation and tap in the plastic screw plugs over the screw holes.
7. To create the restricted ventilation position, open the bottom sash to 12.5 cm.
8. With the window open in this position, place the bolt through the bolt hole on the lock body and gently tap the bolt with a rubber mallet so that the position is marked on the rear sash window frame.
9. Close the bottom sash to reveal the bolt mark. Drill a 10mm hole for the bolt.
10. Check the lock for smooth operation and place the rivet plate in the hole to finish.