36 tooth sprocket video

That's a 44T (your original). If you're getting 30MPH now, you can expect about 35MPH with the new one (30MPH * (44T / 36T)). If you have the standard #415 chain, you can remove links using a standard chain tool (about $10). If you have #41 like I do, invest in a Dremel tool and grind out the pins. Good luck, and WEAR A HELMET!

I highly recommend that you install the "tensioner" if you haven't already; this can sometimes take up the slack you'll experience after installing a smaller sproc. If it doesn't fit well after that, I suggest you remove one link at a time (actually, TWO links: one-wide, one-narrow). You'll need a narrow-link on each end of your chain if you have only the king-link. You can fine-tune with a half-link if you have one.