Hi. Looks like this was from a couple of days ago so hopefully you got it off by now If not, turn your shoe over and in the back of the pedal you should see a screw with an opening for a small allen wrench. Put an allen wrench into that hole and turn it counter clockwise until it's loose enough to get the shoe out. Remember that you get out of the pedal by kicking the heel away from the bike.
You'll want to adjust that screw so that the shoe is tight enough on the pedal that it doesn't wiggle but loose enough that you can get it out when you're done working out.
If you're still stuck and that doesn't work, let me know