As an alternative to the steps described in Step 12 the following procedure may be preferred:-

Fully retract the bolt and put a spot of paint in the centre of the bolt. Then close the door or window fully and then using the manual over-ride key drive the bolt into the locked position until it touches the frame, then retract the bolt fully.
When you open the door you will see a ‘dot’ of paint on the frame marking the position to drill the bolt hole into the frame.