Solutions for pedals screwed in the wrong sides?
I doubt that you actually managed to screw your pedals into the wrong sides.  If it can even be done, the amount of force required to do so would have easily alerted you that you were doing something dreadfully wrong.  Not to mention the aluminum shavings that would have been all over the place.

Pedals can get pretty snug just through the action of peddling the bike and it may take quite a bit of force to get the unscrewing action started.

Also remember that crank arms and pedals are threaded so that the action of pedalling the bike does not cause the pedal to loosen and fall off.  This means that on one side of the bike, the right/chain side, the pedal is threaded as a regular clockwise to tighten, counter clockwise to loosen bolt.  The left-hand crank is threaded in the opposite direction.

Don't be afraid to apply a good amount of force (in the right direction) to loosen the pedals.  If they are threaded correctly, it would be quite difficult to ruin them by applying too much force.  If they actually are threaded incorrectly, the crank arms are ruined anyway, so you're not going to make things worse.