Upper and lower rollers on sliding mirror closet door

I need to replace the upper and lower rollers on two sliding mirror closet doors. One of the doors is missing a roller at the top as well as the guide at the bottom and that entire trim piece can be pulled off. I am sssuming the top roller piece and bottom guide somehow hold the unit together?

I have attached pics.

Thank you.

Rob

Thank you, I will give them a try.

Rob