Just thought I'd let you guys know how I got on. My regular garage removed all 4 for me, fitted me a new tyre all for £65 so I can't be unhappy with that. They used the plasma cutter to get the collars off, my wheel nuts are hidden behind the wheel cover so I told them beforehand to use whatever was the quickest method for them. (saves me a bit of labour)
I've just fitted normal nuts to replace the locking ones.
Now to treat her to a new satin silver gear knob (thank you MK4 mondeo) & 4 new wheel covers (been meaning to swap them for a while but the £17 each cost on ebay kepy putting me off).