Cleaning and Stain Removal - Please help! Mold behind the backplash

We just bought a condo and have replaced the old formica coutertop with granite countertop yesterday. When I was watching the worker removing the old backplash, I saw two areas on the wall (close to where the faucet is) with mold due to the broken old backplash. Before I thought about it, the worker has installed the 4'' granite backplash on the countertop. Now after sleeping on it, I am more and more concerned about the mold areas. I should have stopped the worker putting on the new backplash and removed the mold first. Now what should I do? Is it possible to remove the 4'' granite backplash, cleaning up the mold, and put it back on? Any help is highly appreciated!

let it be. If you have stopped the water from getting to it it will die. The mold is basically sealed between the wall and the back splash.

Thank you so much, airman! This has been haunting me after reading some article saying that the mold will cause horrific problems to the health and the house. I really appreciate your reply! Such a relief!

i would agree with airman that its not worth opening up the area again...but just FYI mold can lay dormant in areas for a long period of time...waiting for the right conditions to grow again..i have run across remodeling projects were the water damage happened years ago and its still there