[aperezd]

Hi,
I am going to replace the masonite crap, oops masonite siding that is rottening on my house taking it off and installing premium vinyl (the one with the insulation attached in the back). The building code and manufacturer instructions say I need to install sheathing board (plywood or OSB) and weather barrier (tyvec) behind the siding which I plan to do as well.
My question is: How do I flash around the old windows when I install the plywood/OSB and tyvek? All the instructions for window flashing I have seen describe a frame, then sheathing then flashing/window/weather barrier type of new construction installation.
Do I have to take the old windows off and reinstall with new flashing over the plywood/OSB? If I do this I will need to build out the interior trim since the window will be pulled out the thickness of the sheathing. If I don't pull them out and I bring the sheathing/weather barrier to butt against the window frame, How do I flash it before I install the outside trim around the window and cap it? Also any comments on the "Never Rot" PVC trim material? seems like a good alternative to wood that will eventually rot around the window.
Thanks for your help.
Al