Can I fix focus play mysefl?

[OhNo]

I got an 20mm Ai-s Nikon lens from Japan over ebay. It's in perfect condition, except for the fact that there is some "play" in the focus. I'm using the lens for video, so I can't have a shaky image when I focus. It'll be costly to send the lens back, if I'm able to at all. Is there a way for me to fix this problem myself?

 

[Derrel]

Find a wide latex rubber band and put it around the barrel and the focusing ring. Not kidding.