There's really not much to it - firstly you need to contact the Inland Revenue and tell them your situation and they'll send you the relavant bumf in the post for you to claim VAT back and register your 'company name' ie; YOU.
You should avoid an accountant if you can as they'll rip you for some of your hard earned, however you don't wanna screw up and end up doing a Ken Dodd... however, the IR literature which they'll send you explains it all pretty much.
Best advice I can give is to collar one or two of the FI's at your airfield and ask them how they go about it - us FI's are usually an amiable bunch and I'm sure one will happily spend 20 minutes with you, showing off how they manage to bleed a little more from the system than the next man.
VFE.