I've just purchased a set of Polysport Bushes from RallyDesign, however like all good things they don't come with any proper instructions

The car is a Mk4 Escort and the bushes I intend to fit are in the rear arm (the rest are going to be ford bushes)
It seems some bushes replace the outter sleeves, but with the polysport ones I'm guessing I have to use the old ones that have stayed in the arm when I removed the old bolts, what I cannot understand is that if I fit the arm/hub bushes in the same way as the old bushes I cannot see how they go in. Has anyone fitted these bushes before and have they got any tips / pictures to help.
Thanks
Steve