Your sissy bar is only has strong as the weakest link its attached too. 1/2" or 3/4" breaker bar?

I went to Harbor Freight and got a 3/4" x 25" breaker bar for $15-20 but they didn't have a 3/4" 32mm socket so used a 32mm 1/2" drive with a 3/4" to 1/2" adapter. I think the total cost was $30-35.

Thoroughly soak with PB Blaster and slip a steel jack handle over the 3/4" breaker bar...I guarantee you it will come right off.