I've never done it but this seems to be the only way as the milled edges are formed to cut into and grip the blade when fitted or it would just slip when cutting.
The milled edges of the ring I'm told cut into the blade bore to form a secure grip of the blade.
Find a board of a suitable size that enables the blade to be laid flat and not sitting up on the cutting teeth.
Ensuring the blade is flat on the board place the board on a solid surface, place the ring square over the bore hole and a block of wood on top of the ring and strike a firm blow with hammer or mallet.
On completion ensure the ring is flush all around the bore hole with no lip ie:in cockeyed it must be flat with the profile of the blade to ensure it runs true 90deg when fitted. I would also recomend you make your future cuts with this ring fitted slower than you would with correct sized blade until confident its ok and when blunt get the blade of the correct bore next time, and don't use a blade of a bigger diameter than the recomended size for your saw, even if it looks like it will fit as the clearance gap between blade and guide/cover plate ends are there for a reason.
Have a look at www.expertvillage.com its brilliant video's on using a table saw amongst other things. Doesn't show insertion of reducer though.
Bob, May 2009
