My US citizen wife used the T5 airside VAT refund facility airside last year. You present the VAT refund receipt to the customs desk along with your passport IIRC. She was given a refund voucher which she took to Travelex who asked her what currency she wanted her refund in.
All very quick and painless!
Last edited by GaryK84; Jul 10, 2012 at 6:11 am
Reason: Missing word