Our house is 50 years old, cabinets are probablly that old as well. After pulling off the old countertop I found that the cabinet tops are not level and the company won't template for me until it is. How can the cabinets be leveled without shimming from underneath the cabinets? Removing the cabinets is not an option. The tops are off at most around 5/16, depending on the area that is checked. Thanks is advance for any help.