Removing Urine Stains From A Mattress. Step 1. To remove urine stains from a mattress will require the use of vinegar, water, a spray bottle and clean cloths. Step 2. Make a solution using half water and half white vinegar. Pour the mixture into your spray bottle to use for treating urine stains in a mattress.Step 3. Remove everything from the mattress such as sheets, mattress covers and pads, blankets, pillows and other bedding items. Step 4. Spray the urine stain that is on the mattress with your vinegar and water solution.emoving Urine Stains From A Mattress. Step 1. To remove urine stains from a mattress will require the use of vinegar, water, a spray bottle and clean cloths. Step 2. Make a solution using half water and half white vinegar. Pour the mixture into your spray bottle to use for treating urine stains in a mattress.