Just trying to get my chain on so I can ride!

Ok, so I took everyone's advice and got myself a great chain and sprocket set from sprocketcenter. Now I am in the middle of the project and have a few issues...

I realize NOW that I should have taken the front sprocket loose first so I could use the chain and brake for tension to get the front sprocket bolt loose. Since I didn't do it that way, anyone have any suggestions on how I can accomplish taking the front sprocket off with the chain already removed? (Yeah, in pretty proud of myself for getting as far as I did)
Also...
From what it looks like, the front sprocket looks alright (but I'm a brand new "mechanic" so what do I know?) but I was wondering if the sprocket should have that much play?

https://youtu.be/ln5mI7ccYPg

Also when I took the three bolts out of the thingy to get to the front sprocket (ok, I just looked it up - it's the clutch slave cylinder) the LONG bolts were badly rusted.

I was afraid to attempt to pry the cover off, so I left the short bolt in tact, and continued to gain access to the front sprocket.

This leads me to a few questions...
1.)How do you suppose those long bolts got so badly rusted?
2.) Should I attempt to gain access to the clutch slave cylinder so I can see what it looks like in there (not that I would be able to understand what I'm looking at)?
3.) How should i remove the rubbery feeling grime from the sprocket surroundings and cover?

Sent from my Z987 using Tapatalk

 

Put the chain back on along the top of the sprockets, doesn't need joining, pu you foot on the brake and undo the stud on the front sprocket. Just dig the gunk out from around the sprocket with a screwdriver or something similar

 

You can't really tell if that's too much play since there will be some movement due to the design. You'll need to check out the splined shaft closely and see how the new sprocket fits. You will have a little lateral play, very little, but no rotational play. If you run your fingernail along the splines you shouldn't feel any kind of lip or worn spot.

Do as NormK recommended to remove the sprocket nut. When you replace the sprocket use some anti-seize on the splined shaft. This will help keep wear to a minimum.

Don't worry too much about the rusty bolts. Replace them if you want to, or use a little emery paper and some anti-seize/grease on the shaft when you put it back together. Mine looked very similar to yours.

If the clutch works fine don't mess with the cover. "If it ain't broke, don't fix it."