How do I light the pilot light on my worcester 240 combi boiler?

I had a new diaphram fitted on Friday as the boiler would no longer heat the hot water and when I returned from holiday today my heating and water only worked until I used my washing machine. Is this just a coincidence? Also, the pilot light is out and will no longer come on to heat the water or the radiators. Its freezing and I'm in desparate need of some heat, please can you help me? I look forward to hearing from you. Regards, Leanne