Cant get track bar bolt out of the bracket on my 1968 Chevy C10

[HeavyHauler]

I am trying to remove the factory rear differential track bar on my 1968 Chevy C10 short bed fleetside and the bolt that goes through the bracket on the frame side will not come out.

I was able to remove the end connected on the 12 bolt differential but the frame side bolt will not come out at all.

What is the trick in getting that bolt out of the bracket so I can get the track bar out of the bracket?

The track bar is factory and looks like it has never been removed before most likely.