Lower Shock Mounting Bolt Removal?

[85 Capri]

I am trying to change out rear shocks on my car with 7.5 rear end. I've searched this topic endlessly with no luck. How do you remove the torx head bolt since there is no nut? It's just a sleeved clip type fastener that just spins with the bolt. Shock is leaking very badly, hence all the buildup in the picture.

[gr79]

Wedge and hold something in there like a large screwdriver or bar against the nut to keep it from spinning.
Impact guns work good here. So fast, nut cannot keep up with the spin.
Or take it to a shop have them break it loose.
Add a shorter bolt and nut to reinstall or change over to the later style shock bracket.
The bolt on there now looks too long.

[dagenham]

That bolt looks way to long. It looks like it is hitting the control arm.

[Greywolf]

That might be worth just cutting off and getting a new bolt and nut. It's definitely the wrong bolt.
I second the suggestion of getting the bracket for the later style mounting bracket; I seem to recall them being about $8 each last time I bought them and they get rid of the problem you're having there; additionally they came with the hardware you'll be spending almost that much on if you DON'T swap over...

I think I got mine from Tasca Ford Parts, but it might have been a package at Speedway Motors. It was a while ago.