Wow. Never seen one of those break for no reason. WTF?
Anyways..you will need to jack the car up, remove the wheel, loosen the lower strut assembly mounting bolts, loosen the remaining upper nuts from those bolts in the pic, then slide the entire strut assembly from under the car.
If you have spring compressors, you will then install the spring compressors onto the springs, tighten them down securely and properly, then use an impact gun to loosen that nut in the middle. (in the pic). You will then need to replace the strut hat (which has the bolts built into it) with a new one. Then re-assemble.
alternatively, you can remove the strut housing from the car as described above, then take the assembly and a new strut hat into a local garage, and have them use their tools and experience to swap strut hats.
Messing with springs/spring compressors is NOT for amateurs. The force in those springs literally can KILL you if you dont use the compressors properly.