I would say try it yourself... that's how you learn it. If you muck it up, then take it to the shop and confess failure

Pedal tip.... With the unused end of the wrench pointing toward the sky, both pedals will loosen by pulling toward the back of the bike and tighten toward the front. That's how I remember it anyways... your mileage may vary.

Look for the L and R on the stem of the pedal to figure which one goes on which side.