69 dart bucket seat track disassembly

Have a bench seat / tracks. Want to get a couple more inches of space so I purchased the seat bracket extensions from year one. To remove the mounting studs I need to disassemble the tracks as the rear stud heads are covered by the little plate the rollers run over. I’ve done some searching but to no avail. I am looking for some help.

all advice is appreciated. Not the best photo but I hope you get the idea. Stupid me, bench not bucket....