Pop out the two round rubber pieces to expose the window bolts.
Lower the window a few inches to expose the window bolts. If your door panel has an airbag on the back, keep the door panel and wires connected to avoid triggering the airbag (SRS) light. If you trigger the airbag light, you will need to use a Mercedes-Benz scanner to reset the light.
Align the window frame to the access holes and use a T30 Torx drive to loosen the bolts. Do not fully remove these bolts. They need to be loose.
Using the palms of your hands, hold the glass window to prevent it from going down, then using the window switch, lower the window all the way down.
If necessary, move the glass up and down to get it loose, then pull it up.
Slowly lower the glass, then remove it by pulling it up but getting out of the rails. Finally, remove the glass from the door.
Prepare the new glass window. Please insert the new glass window into the door slot and lower it to the bottom. Then move the glass up, ensuring it is sliding correctly in the rails.
Position the glass window so that the bottom end of the door glass will be level with the access holes. Tape the glass at this location or have a friend hold it here.
Raise the window riser using the window control until the frame reaches the end of the glass window.
Reinstall and fasten window bolts. Don't overtighten, or you will crack the glass. Also, make sure the window brackets have rubber pieces; otherwise, the glass may break.