Strip the bed and remove all bedding
Vacuum the mattress thoroughly on all sides
Spot clean stains with a mild detergent solution
Blot stains with a clean cloth
Use baking soda to deodorize the mattress
Let the baking soda sit for several hours
Vacuum the baking soda off the mattress
Air out the mattress if possible
Flip or rotate the mattress if needed
Use a mattress protector after cleaning