Quite simple really. Just place the rubbers in the hub so that the bottom edges of each pair of rubbers are propped up against each other so as to form a V where the vanes on the sprocket fit. Align the vanes and push together. Thats it!
You can always apply a little tyre lubricant as used at your local tyre fitters if you want to make it a bit easier.
Dave Bushell (Club Librarian)