If you can verify 7 yrs of aviation maintenance experience then there is no reason why you can't sit the prerequisit exams at the next available sitting and have a licence in your hand within a fairly short time frame. (this of course assumes you could actually PASS the exams))
The crux as far as the UK CAA are concerned is experience. Once you have this you can take exams in your own time as and when you feel confident of a pass.
Bristol's Brunel, Southall Tech, AST in Perth (among others) all do short refresher courses.
There are some web sites (airmech and club66.co.uk) which have a bank of questions gleaned from exam students to help study the modules.
Check out the CAA web site for knowledge requirements.