Generally, it's nearly impossible to change the level of firmness once you've bought a mattress. However, In Winco Foam Industries, there are still ways to fix the problem. 1. Take advantage of our 14-night Risk-free trial periods: If the mattress you've just bought is too firm or too soft and you're still within the trial period, you can simply return your mattress 2. Mattress toppers: If your mattress is too firm or too soft, then you can buy a mattress topper to soften up a firm mattress or add cushioning to a soft mattress.