how to set clock?

we have a vokera (the linea range) combie boiler which was installed about 7 years ago. Unfortunately we have lost the instructions for how to re-set the clock (due to power failure).
We wondered if you had any instructions you could send us. The clock is a round dial with eack quarter on the side to adjust then a small dit betweel them which you need to press in with a small piont to adjust it. Sorry if these instructions are very vague but without drawing it it is hard to explain. Hope you can help.