where do i find the part number/code for the injectors? on 1999 Volkswagen Golf

I actually have a 1999 Golf 2.3 V5 (your drop down list doesnt list it). I am also in the united kingdom so your "zip code" wont accept my digits so I have used one from florida.
Its got a faulty injector on cylinder 5. I have some options on ebay to buy a replacement but I need to ensure I get the right one, with the right part number/code.
I just need to know where to find the part number so I buy the correct replacement.

Asked by for the 1999 Volkswagen Golf
you must remove the injector to get the info you need.

1 more answer
Do not know your skill level.Why are you changing injector ???