Guys,
If anyone is pondering on whether they should give it a go, I would highly recommend they would. I am by no means a mechanic or a technical person. I have never dismantled a car door let alone a 350Z one. Just follow the guide step by step to the finest detail in order to avoid any mishaps and in 3 hours you will have a functioning window without spending any money.
I have a 2008 and the passenger window was the problem. To remove the door card I found a short guide from the following site
http://my350z.com/forum/audio-video-and-electronics-diy/407151-2008-door-panel-removal-front-speaker-install.html
Then used Steve's guide to do the rest. I should thank Steve himself for the 'online' help he provided while I was doing the job.
Window is functioning well and hope it will for a long time. I am happy to help if anyone has any questions as I am sure all the others would.