Device to Compress Hydro Comp Spring

Does anyone have a device to compress the hydro comp strut on a 108 or 111 rear axle? I have the replacement, and the CD manual shows a "Clamping Device" but the pictures are not clear as to design etc.

Any details would be helpful. If you have a device that worked, i'd pay to ship and return plus rental fee.

thanks in advance,

steve