Can I Remove a License From an Active User in DSLS

I have some work to do on some of our CATIA macros over the holiday period, however I am unable to modify some of them because they are open in an active CATIA session. In the license server tool I can see two people are using a license, which means they've left CATIA open when they finished for Christmas.

Is there a way to take those licenses away from them, even though they are in use? I thought I could use the recycle function, but that is greyed out, so maybe it only works when the license isn't in use.