Blot up as much urine as possible with clean paper towels or a dry cloth
Remove bedding and wash it separately
Mix equal parts white vinegar and water in a spray bottle
Lightly spray the stained area without soaking the mattress
Blot again with clean towels
Sprinkle baking soda over the damp area
Let it sit until completely dry
Vacuum up the baking soda
If odor remains, repeat the vinegar and baking soda process
Use an enzyme cleaner made for urine if the stain is still present
Let the mattress air dry completely before remaking the bed
Place a waterproof mattress protector on the mattress afterward