Right then, i've been having major issues with creaking doors, i thought i'd sorted it at one point by claying and sealing the apateur (sp) but as it turns out it was only a temporary fix

So the car went in on saturday for Service, cruise fitting, door seals and the damn clunk coming from the off side rear qtr! They've told me it needs booking in for a whole day to have ALL the door seals replaced!

internal and external, now in on one hand i'm pleased that even though the car is 2 years old they are still willing to do this, on the other hand i'm a bit nervous as to what is required for this?
It's being done regardless because the creaks are unbearable to me, my wife and 90% of other people that get in the car but can someone tell me whats involved to replace these seals? Particularly the external ones.
Cheers chaps.
James