Loosen the wheel, push it forward in the drop out to create some slack in the chain, push the chain off the chain ring (holding ther chain line off centre while slowly turning it backwards, carefully so you dont jam your fingers). Then unhook it from the rear cog and slip the wheel back and out.
To put it back, slip the wheel back in, hook the chain on the rear cog, then make sure the wheel is loose and forward in the dropout, hook it on a couple of teeth on the chainring, and slowly turn the dedals forward while guiding the chainline such that the chain guides itself back onto the chain ring. Pull the wheel back to tension the chain. Tighten the wheel (nice and tight so it doesnt slip forward when acelerating hard).
But.......... you dont need to remove the wheel to fix a puncture. Just whip the tyre half off, loosen the valve nut, and slip the tube out, it will still be attached to the bike but it will allow you enough freedom to find the puncture and make the fix.