- Decrease trim has a 7mm screw and T20 screw. Eliminate and pull down really hard. Not necessary to remove decrease trim for 2018's. You merely will need to interchange your switches. There’s an incredible youtube tutorial by CJPonyParts on eradicating the wheel and replacing switches. Which is located here: https://laghinggasprerolls98259.thenerdsblog.com/37607656/5-simple-techniques-for-2015-mustang-gt-digital-dash