I don't know how to break this to you.
You should be sitting down.
If I remember correctly, you're going to have to take the drive shaft off or separate the flex coupling.
Here's what you'll see when you get the drive shaft & flex coupling off the pulley:
I discovered this after replacing a shaft with a worn out spline.
After I got everything reassembled I realized I hadn't replaced the fan belt.
There was a few minutes of head scratching before I realized that I had to take that shaft back out if I was ever gonna get that belt on.
Doh!
If you replace that belt make sure you get a good quality replacement that will last a while.
What Baby Grand said, and for sure don't get the screws 130 and 140 mixed up, they are different length and will offset the drive shaft and cause it to vibrate.