this article says it covers 2014 models as well, so i'm guessing brakes are similar between 2IS and 3IS.
If true, then the 3IS 250's all have a very common brake pad change procedure.
The only change I would make to that article is when it comes to the 14mm bolts holding the caliper in place, loosen both bolts, but only remove the lower one. By leaving the top 14mm bolt in place but loose, you can pivot the caliper upwards and remove the pads. That way you don't need to worry about where to place the caliper so you don't tear the brake line. Simply, pivot up, remove pads, install new pads, push piston in, and pivot down, tighten the caliper into place.
Rears should be similar except you probably can't pivot the caliper in the rear due to the E-brake, so you'd have to remove the caliper completely.