You will probably need to check for coils just in case, if there's a plastic top on the fridge remove it first, then, if it's just foam, kinda poke around in the foam where you want your tower to see if there's any tubes. if it's metal on top, paint the top with a mixture of corn starch and rubbing alcohol then plug it in and turn it on. if there is a coil running through the top it will heat up and cause the "paint" to dry in a line where the coil runs. This worked for my kegerator, Hopefully it will work for you. it would suck to drill through a line and have a big expensive doorstop.