CJPP has posted this great instructional DIY video on installing a set of Eibach springs (applies equally to any brand springs) in the 2015 Mustang.
Installation is pretty simple, but there are a few more steps involved with installing the rear springs due to the new independent rear suspension.
The full install is estimated to be about 2-3 hours, which is time well spent for the improved performance and looks!
See the VIDEO inside.