How to remove the drive pulley, and install a new Woodruff Key?

Question edited for clarity.

Disassemble, replace any worn or 'crunchy' bearings, replace ALL seals.

Limited help here

https://www.google.com/search?q=peerless+206-545C

more here

https://www.google.com/search?q=peerless+206-545c+rebuild

Full Parts Diagram

https://www.manualslib.com/manual/497385/Craftsman-917-273811.html?page=48

Service and other manuals

https://www.google.com/search?q=peerless+206-545c+service+manual

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Thought I posted a solution earlier on this, but it was my first post and I don't see it here so I'll try again.
Google search on your model shows the drive belt diagram on page 27 of the manual.

link below:
http://www.mytractorforum.com/images/reference/dgs6500.pdf

Looks like mine.
basically need to remove front pulley by loosening center bottom bolt while holding the center nut on top of motor.
Slip belt over the rear pulley first and then straight toward the front, slip belt on front pulley and then slide pulley back onto shaft.
Then wind through the rest of the pulleys etc..as seen in the diagram.

I just did this. You may need a second set of hands.... Remove the mower deck & back plate. Depress the clutch (this shortens the distance between the pullies.) Pull the belt slack toward rear of the tractor. Remove belt upwards from the transaxle pulley by deflecting belt keepers. Pull belt toward front of the tractor and remove downwards from around the engine pulley. Install the new belt by reversing the procedure. NOTE- there's a diagram of the procedure on page 24 of the owners manual (which I downloaded when I couldn't find my original)

If it is the drive belt do the following place your mower on a level surface set parking brake, remove mower deck, remove belt from stationary idler and clutch idler, pull belt slack towards the rear of tractor , then remove belt upwards from transaxle pulley by deflecting the belt keepers, then pull the belt towards the front of mower and remove downwards from engine pulley Install new belt in reverse procedure

lift the front of the tractor up at least 3 feet and lower the mow deck to give you clearance. push the clutch pedal and lock it down to release belt tension. remove the mower belt from the engine pulley only. remove the trans belt from the idlers about midway back then from the trans pulley & finally from the engine pulley. put the new belt around the engine shaft above the mower drive pulley but not on the drive pulley then around the trans pulley. now you can put it on the drive pulley and finally on the idlers. make sure you have it under all the various keepers or the belt will shred in like 10 minutes. release the clutch pedal & check the belt again to ensure it is in the correct place. replace the mower drive belt & ensure that didn't come off other pulleys in the process. lower the front of the tractor and test

@the rear of the tractor bottom left you'll see a metalrod sticking out and if it hasn't come off a decal with a picture of man pushing tractor that's it.

SOUNDS LIKE THE BELT HAS CAME OFF OR THE PULLEY HAS BROKE

Check the drive belt that runs back to the transaxle,it sounds like it broke.If the belt is in the pulley check to see if the transaxle pulley is turning when the clutch is out.Also make sure both wheel axle keys are in the rear wheels.If all this checks out the transaxle may have broke,look underneath to see if it is broken there.

Is the transaxle pulley turning? If so have you removed the rear wheel recently and possibly lost the square key that fits on the axle?check those two items first.If ok it probably has a broken gear or shift key in transaxle.

you remove shield from engine remove belt, remove deck from mower and remove pulley guards and install belt replace guards , reinstall deck, put belt on engine pulley replace guard