First thing you do is pull out your refrigerator and clean all the dirt out from behind it.
Then you take the back off the rear lower part of the fridge and clean all the dirt out around the coils.
And vacuum all the dirt as you carefully brush the coils..
You should do this this about every two years, or more if you have pets.,
IF YOU DO THIS your refrigerator will last 20 to 30 YEARS .
I have only bought 3 refrigerators in 60 years !