Once you have the sliding unit back in the door frame you can adjust the rollers for optimal performance.
How to install new rollers a sliding glass door.
Replace the roller screws and use your phillips screwdriver to turn them clockwise until tight.
Insert the new rollers in the door lining up the holes on the rollers with the holes in the bottom of the door insert the new rollers in place.
Slide the new rollers into the bottom of the panel.
Keep adjusting the rollers until the door is sliding back and forth easily.
Make sure the rollers spin sufficiently before re installing your sliding glass door.
To make it easier to install the sliding unit back into the door frame adjust the rollers to be all the way up into the frame.
Use the old rollers as a guide for installing the new rollers.
The holes for the screws should line up with the holes on the door so that you can screw the rollers into the door.
You can find replacement patio sliding glass door hardware here.
In this video we show you how to replace a roller in a patio sliding glass door.