Too much oil

I just did an oil and filter change on my 1980 KZ440. The Clymer manual said to add 3.1 quarts of oil with the new filter. When I first started the bike there was a fair amount of smoke and after riding it around for about 15-20 miles, I noticed that there was some oil leaking from the right side of the engine (along the gaskets on the bottom of the clutch cover and I think a bit from up near the cylinder gaskets (?))

When I saw this I checked the oil level and it indicates that there is too much oil. I plan on taking some out this afternoon. Two questions:

1) What is the best method to remove oil and make sure you haven't taken out too much? I was thinking about just putting it up on the center stand, pulling the oil drain plug, and keeping an eye on the oil level window until it reached the right spot. Otherwise it seems like it will be a messy trial-and-error type of job.

2) I'm afraid I may have compromised those seals/gaskets by riding around with too much oil. Do you think they are permanently damaged, or once the oil pressure goes down after taking some oil out, I should be okay?

Drain some out via the drain plug and get it to just above center of the sight glass when on the center stand. Then clean up the leaking area, and take it for a ride. See if it leaks. If so then you will have to repair those seals/ gaskets that are leaking.

Stick a piece of clear plastic tubing in the filler hole and siphon some out.

You can get something like this at most drug stores. I get mine dirt cheap at American Science and Surplus. Very handy to have a few of them around.

Do your checking with the oil hot too