Re tighten the side you got loose then put your socket on the other side.
Tap the ratchet with a steel hammer so as to break it free.
The best way is with an air tool to "Shock" the bolt and break it free.
This is normal and can be a real pain in the A_ _ but it will break free.
You just have to break both bolts loose before you remove anything.
Sometimes it helps to do this while still under tension of the track, similar to breaking your lug nuts loose on your car before you lift it up.
