another good way to compress the springs (if you don't have ratchet straps) is to take a thin rope or old tie down strap and snake it down the inside of the spring along the shock from somewhere around the top of the spring, then loop it out of the spring towards the bottom so if you pull the two ends together they compress the spring. Take a screwdriver and
tie the ends of the rope to the center of the screwdriver. Then just twist. As you rotate the screwdriver, it will twist the rope and cinch the spring together. Do this for the opposite side of the spring also.