Nothing really hard about it, do not push it in really hard or you will lose your r-value, it is designed to lay in between the studs snuggly also where there is wiring running through the wall studs tear the insulation in half and slip it over the wires so you have insulation behind and in front of the wires.Wear a dust mask, gloves, and full clothing. A little tip now when finished for the day take a shower and dry yourself off and then shake baby powder all over yourself. This really helps control the itching.