I just used a regular brake tool to disassemble mine, similar to your set-up. The brake tool gives you the leverage and hook to slide the springs down the tool.

1957 Chevrolet 5700 LCF 283 SM420 2 speed rear, 1955 IH 300U T/A, 1978 Corvette 350 auto, 1978 Yamaha DT175, 1999 Harley Davidson Softail Fat Boy