Thanks for the responses guys, I didn't realise it would be so difficult to remove the side rails. I thought they were just bolted on, luckily I asked first or I could have done some real damage trying to pry them loose. Since the new side rails didn't come with the adhesive, will any double sided tape do or is a particular type of tape required? 
Matthew
On the ones I did on my T2, I just used this thin semi-transparent double sided tape. It worked OK but not 100% happy with it. IT was just the regular stuff from spotlight. I just pulled the ones off my Getaway and it was this wide black heavy duty looking stuff. I will be interested too see what others say.
I was thinking of getting some automotive double sided tape...-
