Ha. My first post here. I just finished the glass change on my Leon. Don´t buy whole door if it is not real bargain. It is too late to
help you with "
how to do
guide" to dismantle the glass, but it is pretty simple job
What you need to do now is to strip down the doors. There are several screws around the metal plate. You need to disconect all the cables etc. but you will find out by yourself. You will push the plate little bit up to get the clearance for the guiding lines of the window and take the plate of. Inspect the mechanism. There can be several defects. Consedering the symptoms, I believe that you will have the
problem with the metal string moving the guides, or plastic wheel on the motor. Order just the damaged part and glass. Once repaired, put the plate back in place, move the guides down without glass. Put the glass from outer side of the doors by diving the fron side of the glass into the doors and when approx. half way in, start lo level up the glass into horizontal position. Then tape the glass into door frame. Move the guides to the position, where you see the screws on the guides in mounting holes. Untape the glass and put into the guides. Check the placing and tighten the screws. And YOU ARE DONE!
sorry for english, if some mistakes..