Looked hi and lo on you tube, etc. couldn't find a video that matched my machine. Solved the issue with Yankee ingenuity.
Moved shift linkage out of the way so I could see what needed to be moved. Started with removing the large nuts at each end of the hex shaft.
Next was removing the bearings on both sides of the hex shaft. I needed to modify a 3/8" open end wrench to reach the nuts in the innermost part of this snowblower. There is a spring (part of the friction plate adjustment) that was in the way so I moved that out of the way which made it easier to move the small sprocket out of the way.
Once the bearings and their housing were out of the way I had to drill a hole in the right side of the machine using a step drill creating a hole of 3/4" diameter, which was just large enough to slide the hex shaft over to the right and get it clear on the left. Next I had to remove the shaft that the fork slides on. Drove it out from right to left using punches and ball pein hammer.
Took the friction disk, hub, and fork over to the vise where I remove a retaining spring that allowed me to separate the hub with the friction disk on it.
Five bolts late the friction disk was removed.
Now I'm waiting for new disk to arrive.
Pictures for reference
Hole drilled in side of machine allows enough play in the hex shaft to be able to get friction disk and hub out.
Drill small hole to get started the use step drill to enlarge the hole to the largest size on the bit I used.
Heated wrench with Mapp gas torch until cherry red, bent at 90 degree angle to access difficult 3/8" nuts on interior of machine
Drill hole so it's approximately inline with the hex shaft. I'll get a metal cap for the hole when job is complete. other holes are for shift linkage.
Photo #3 illustrates the large nut (one on each end of the hex shaft) and the four 3/8" nuts that separate the bearing carriers
Photo#1 Illustrates the starting point after removing the transmission pan and tipping the machine up on its front. You can visualize the large nut and the bearing hiding behind the shift linkage.
Sorry I didn't place the pictures in the correct order. I hope you can make sense of the procedure.