NEED SPRITING HELP

Here's the thing...
I need this city in the map to look like it's been eaten by that creature. I'm in need of some spriting help to edit the building tiles.

Nothing too fancy, I just need the buildings in the zone marked red to look like it's been partially eaten/destroyed. If you're willing to help, just edit over the right image, and I'll use the final result as a picture to put on top of the original in the game.

Hope it's not asking much! Thanks.