drawer slides

[MomboTN]

I have a 2000 Niagra.  The camper is in great shape except the drawer slides.  The drawers seem to fall as the slide out.  I went to replace them thinking I could unscrew the old ones and replace them but the old ones look like they were rivoted in place.  I would like to fix them but am not sure where to start.  Any help would be greatly appreciated.