I have an Amana side by side refigerator and the coils underneath it are dirty. I tried to vacuum and use the cleaning brush but there is a metal grate that blocks it from being completely cleaned. How can I remove this grate or clean behind it?

You can use caned compressed air and blow it out,you can buy the air at computer stores or large hardware stores. Just an idea.

You can purchase an appliance brush to reach. It cost about $6 and available at an appliance repair shop. Possibly at Lowe's or Home Depot.

You can get the appliance brushes at Wallyworld for less than $5. They have a real long handle and skinny brush. Be sure to turn off the fridge while you are cleaning the coils so just in case you push the brush in too far you don't wedge the brush into the fan at the back of the machine. Don't remove any metal unless it is the metal drip pan. Try and see if this is what you call the metal grate. You need to clean the small metal fins of the built up lint and dirt as much as you can.

Pull out and down.