The holes for the screws should line up with the holes on the door so that you can screw the rollers into the door.
How to install new rollers a sliding glass door.
Use the old rollers as a guide for installing the new rollers.
Slide the new rollers into the bottom of the panel.
Make sure the rollers spin sufficiently before re installing your sliding glass door.
How to replace the roller assemblies in a glass sliding door i made this video because i needed to replace the slide rollers in my 10 year old glass sliding.
Once you have the sliding unit back in the door frame you can adjust the rollers for optimal performance.
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.
Keep adjusting the rollers until the door is sliding back and forth easily.
The wheels should face downwards.
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.
Replace the roller screws and use your phillips screwdriver to turn them clockwise until tight.