I think that was a one year only deal on Souls that didn't have the turn signals in the side mirrors?
Anyway you should be able to very carefully pry with a couple plastic trim tools. I would start at the pointy end and hold your tongue just right hoping you don't break too many of the clips. Expose the backside and you should be able to access the bulb.
You can not see the inside from any angle, use a plastic body trim tool to pry the lamp assembly out. Disconnect the wiring and remove the socket. A great time to upgrade to brighter, long lasting LED bulbs. BUT, there is not much room for a bulb inside this side marker housing. You need a low profile LED bulb.