Here’s a first stab re. guidance on how to replace the springs.
Take some careful measurements re. ride height. Do this at each corner, picking some logical location and measuring to ground. New springs will allow height to be adjusted a little bit, for good or ill, and you’ll want to adjust them to the same height that they were.
Rear. Get a pair of spring compressors from Harbor Freight. That will squeeze down the rear spring a bit and it will pop out. Put in your new spring and the plastic piece that holds it in place.
Front. Drop your front struts out of the strut tower. This will mean unfastening them from your control arms and sway bars. Cut off old spring perch (optional, but I’d do it). Thread new collar (gold) on to new threaded sleeve (red). Place sleeve over top of strut housing. Put spring in, put new top hat on, insert strut back into your camber plate.
Note that when you reconnect your control arm to your hub, you have to support the balljoint from below. Put a jack under the balljoint and lift the control arm. Otherwise when you turn that balljoint’s nut, the balljoint just turns, taunting you.
Be advised that I’m pulling all of this out of my butt. I’ve not actually installed this specific kit before. Hopefully someone who’s actually installed this kit can chime in and help this thread.
Pickle fork to separate control arm balljoint https://www.harborfreight.com/tie-rod-separator-set-63738.html
Ball joint tool if you decide to separate tie rod end from hub. Don’t use this on control arm balljoint, it’s not strong enough. https://www.harborfreight.com/3-4-quarter-inch-forged-ball-joint-separator-99849.html