You focus a lens by twisting a thing that moves the glass forwards. The further forward it goes, the closer the focus point.
In the old days this was obvious: You could see the lens move as you did the twisting. These days something magical happens deep inside the lens and elves move glass in secret ways.
Anyway, you can force a lens to focus loser by fitting tubes between it and the camera. I have a nice set of Kenko tubes made for the micro four thirds camera range, and here's what you get if you park them on a legacy Tamron 135mm telephoto lens..
That is not too shabby at all. Let's hear it for good old fashioned extension tubes.