Nothing under the dash needs to be messed with. If you look at the new booster you'll see that it's all under the hood. Just make sure you make note of the push rod's orientation it's kind of eccentric shaped with a top & bottom. Basically you have 4 nuts and a cotter pin to remove right near the firewall. Assuming you already removed the Master cylinder. Real easy part to change. Some great pictures are at Google Images. Just search google images for duster brake booster.