Instructions
Travel to the "Town Hall Plaza" as soon as you get the message that Ginny needs your help. The Plaza is the area in the middle of the map where you talked to the mayor at the start of the game and where your house is located.
Tap the house icon on the bottom left hand side of your screen while you are in the plaza area. This will bring up a new screen where you can move objects in the game world around. The "obstacles" that Ginny was referring to are all the blue dots that are marked on your map.
Tap the remove icon (box with a blue arrow) on the right hand side of the screen then tap on all the blue dots marked on your map. This will remove all the lamp posts, park benches and other objects in the area.
Return to your house located in the bottom right hand side of the Town Hall Plaza area and enter it. Use the elevator hidden in the book case to go down to the secret room. Double tap the crate standing next to the sofa to receive some money for helping Ginny and completing the mission.