Even if you offered me the plastic brackets to install so I could cheat and run away, I might encourage you to use something METAL that you won't call me back for, breaking again. For these types or repairs I don't bother to find the original plastic hardware. Any hardware store will have what will fix this for the life of the cabinet: (amazon.com)
Attach them with small nuts and bolts to the slide, through drilled holes you have very carefully measured for to aline it to the correct overall length. Use panheads and insert them going to the outside, so as to not interfere with the drawer.
"Drawer slide brackets":
People in the same exact boat, along with a product recommendation: swisco.com/discussions/Rear-socket-replacement-for-kitchen-cabinet