A manual car window can need repair for several reasons. To fix the window, you will need to determine exactly what the problem is. Gaining access to the inside compartment of the car's door or area where the window is concealed will be necessary. After locating the problem, it's a simple matter of repairing or replacing the problem part. Reassembliy of the parts that were taken off or loosened--and testing the repair--will be the final step.
Remove the inside door cover or panel that covers the area where the window is concealed. Most panels are attached by plastic clips and screws. Use the flathead screwdriver to pry loose the bottom of the panel. Be careful not to damage the panel when prying it off. Plastic clips will snap out of their sockets as pressure is applied. Use a Phillips screwdriver to remove any screws around the edges of the panel. Some screws may be hard to locate. Look closely and you will find them. After the panel is loose, pull up and out to remove it.
Look inside the area where the window is concealed and turn the manual window knob. Check for places where the track may be loose, binding or bent out of shape. See if the gears and moving metal parts need grease. Make sure the window track and trim at the groove in the door or panel where the window slides are clear from obstructions and not worn out.
If you are unable to determine what the problem is, look at the car's other window, assuming it is operational. Take off that door panel and roll the window up and down to observe the correct installation and operation of the gears and track. Most of the time, rust or loose bolts are the problem.
Use open-end wrenches or a socket wrench to replace broken or worn parts or tighten loose bolts and nuts. Test the operation of the window by rolling it up and down before replacing the door panel.
It may be necessary to remove the window to make the repairs. If so, just unbolt it, slide it out of the area, make the repairs and replace it in the opposite order. Pay attention to how the parts were removed so they can be replaced in the same manner and location. Purchasing a detailed auto-repair manual may help with making the repairs.
Always take safety precautions and wear proper safety equipment while operating machinery or using hand tools. Don't apply too much pressure on the glass. It could suddenly burst into thousands of tiny pieces.