I got the seal changed out today, so I guess I'll answer my own question here for the benefit others who have the same repair.
This is the front crankshaft oil seal I'm speaking of. There are no other collars involved - just the seal.
Getting to it takes some time.
- Grill guard, headlights, plastic shrouding, battery, oil cooler, and radiator all have to come off.
- Two steel hydrauling lines going to the steering valve have to be disconnected and pushed to the side.
- The nut on the pully is 46mm and requires a deepwell socket - ideally on an impact wrench. Good luck finding a 46mm deepwell! I ended up using a 1-13/16" on a breaker bar with a chain wrench to hold the pulley. Not the perfect fit on the nut, but it's not too terribly tight.
- Remove the pulley. I used a 3-jaw puller and it slid right off.
- Now you can access the oil seal. I didn't have a seal puller, so I just screwed a small self-tapping screw into it, clamped some vice grips to it, and pulled it out.
- To tap the new one in, I suppose there's a tool for that, but I didn't have it

A deepwell socket isn't long enough. So I used a small block of wood with a hole the size of the shaft drilled in it, then put a deepwell socket against it and tap it in.
- Reassemble.
Hope this helps someone.