seat bracket

I just bought an aftermarket racing seat (because the my stock 1994 corolla's seat is very saggy...tilted..and screwed up but thats another story)

The problem is I cant find a way to take off the stock seat (drivers side only). The seat i bought came with universal sliders, but no brackets.
The stock bolts looks like they're welded into the ground and the stock brackets dont look like they're really moveable. Has anyone done this before?

Can you post a picture? Not sure how the brackets are attached to the floorboard.