The shifted gear usually falls back into it's right position if you knock the clock (not too hard) on the table and turning a little at the corner gears. You can see the nippels in the transparent clock face that have to hold the gears. So you can see the direction your knocking should move the misplaced gear.
And if it does not work: Open the clock (there are YT videos to show how) and bring it together. Maybe a good opportunity to magnetize it.
@CornerCutter has clock magnets that fit well.
Roland