I did mine there today. It took 30 minutes. You can download the TM7 form and fill that in before you go. They give you 2 additional forms at Immigration to fill in so make sure you take a pen
Get an online Revolut account. They give almost the bank rate when you pay for anything on the card. If you upgrade for £72 you can draw out £400 a month at no charge. Also has a lot of other great features. Saved me a fortune!!!