Hello JX and welcome to The Jaguar Owners Club. It is not a big job to resolve the issue with your windows however can become a little tricky. When I have done it in the past it has been a case of removing door cards etc which never seem to go back on the same. Personally I would take it along to a body shop who would be used to such issues, as Peter said don't take it to the main dealer who will only attempt to charge silly money for what can only be described as a simple job.