For these cases there is a special tool with three callipers and a centre screw. With this tool you can pool the blade. On other way is hang the juicer on two metal flat very thick sticks which can be secure in two bricks or thick wood blocks which must be just one inch higher than the height of your juicer., one in one side and second in other. And by using a plastic or wooden hammer you hit over the axis so the blade will become loose and come out.

Under the juicer you can put something soft like a towel so if the juicer falls down to keep it safe.