A few years ago I bought a DIY will kit from, I think, W.H.Smith, for about a fiver. It had very clear and full instructions, which I followed to the letter. I then photocopied it for myself and sent the original off to be deposited at the official place in London (details for this were given in the pack). At the time I think the deposit fee was about £15. They will send you an official receipt. It was much easier than I had imagined. Also you might be able to buy a DIY pack online if your local stationer doesn't stock them? Best of luck 