I've had my door panels off a couple times, I see no problem with a surface mount application.
You have 2 screws in the door grab under the plastic cover.
Take a knee and look under the bottom of the door panel, 2 more
look at the side of the door panel, door latch side, you will see a hole towards the top (1 screw in their)
Start on the bottom and start pulling the panel away. Work up to the top. Old man strength might be required. When all the pins are free lift up and take the panel off. Put a blanket on the ground where your working to keep from messing up the door panel when you set it down. because of the wire length you will be forced to lay it under the door.
You might want to have some double sided tape or spray glue to reattatch the wind/sound (black) panel when your done. If your gonna run off the stock system make sure you got some crossovers for your tweets. If you got the alpine system you might get away with no crossovers.
Should be a pretty simple install, make sure to test your tweets to make sure their what you want before you reassemble your doors.
If you ever sell the car you can just put some of those black plastic pushpins in the holes.