do you mean the little allen head screws? or just the ring itself. sometimes you might need a strap wrench or something to hold it still while you get those bolts. but if the bolts are already out i would just tap it, should come off easily
Hmmm when I swapped mine I tapped it with a rubber mallet and it came off. Maybe try spraying some penatrating fluid around were the ring goes on the hub?
Make sure you hit evenly around the ring so you don't get it put into a bind by not bringing it off the snout squarely. If the bolts had locktite on them I'd probably lean toward locktite running down and glueing the ring to the hub. It shouldn't be held on very tight.
So after penetrating oil and about fifteen mins with a rubber mallet I finally got it off. It's like the center bore of the 2.76 ring is just a touch small for the hub on the blower.