How do i open the area up to retrieve the tool
it slid down into it through the opening under the drivers side windshield wiper then into this hallow area above the wheel
If it's where I'm thinking, you either need to take the cowl apart ... or if the other place, you'll need to pull the fender off of that side. Not a lot of fun either way. If the tool is made of steel, you may be able to get an extendable magnet and fish it out. Not a perfect method, but might save a lot of trouble.