It's seized on the shaft. Heat and penetrating oil will work if you are careful not to overheat the shaft. Sometimes you can heat the outer area and apply a cold water-soaked rag to the shaft to shrink it, then tap the shaft moderately while prying from behind.

I have an Echo ES-210 Shred-N-Vac. I would recommend it. Mine is about 3 years old and I haven't had any problems out of it. The only thing that I would change to make easier is the attachment of the vacuum tube to the unit. You currently have to use a screwdriver on a large band clamp to tighten. The current design is not necessarily poor, but a tool-less design would be more convenient. The ES-210 works well as a blower and as a vac in my use.

With the module over the magnets, slip a business card in the space and loosen the screws. Tighten the screws then turn the flywheel to release the card.

I found a Flowtron leaf shredder at our local ReStore (salvaged building materials and lots of other stuff) for $9.75. These look flimsy, and use a crappy little universal motor (the kind with brushes), but that motor revs very high. Uses heavy trimmer string to chop the leaves. I adjust it to shred as fine as possible. Works even on wet leaves, though slower. Won't take anything larger than very small twigs, for obvious reasons. Because it has a very large opening, you can dump leaves in at a good rate, but not too fast as you can overload the motor, which universals don't like (tends to burn them up). It's surprising how long the trimmer line lasts before needing replacing (which is very easy). I noticed in another thread how someone was using a trimmer in a round wire cage to shred leaves. The Flowtron is the same idea refined to a much more efficient level. Amazon has 2 models, at about $130 and $136. Harbor Freight has a similar one, but a bit smaller and maybe flimsier for about $70. I use mine only for leaves (pine needles too), and have a hammer mill shredder/chipper for everything else.