A fair amount of people will strongly caution you to not use the threaded rod type. I imagine this is good advice.
I did end up using them but I took some precautions. I recommend you to use the correct size for your coils as well as inspect them prior to using them.
I installed Geiser springs on bottom perch on my truck. I used (4) threaded rod spring compressors and I loosely wrapped a ratchet strap around them in case one were to let go. The loose strap would allow the compressor to move some dissipating energy if it were to pop off. I also laid a heavy towel over them if the cast heads were to catastrophically fail to help with shrapnel . When I tightened them I did so in a cross cross pattern and took my time.
As far as removing the existing spring I did the method similar to forged offroad’s video and placed my foot on the spring and took the nut off with an impact and no compressors.
I can only tell you what worked for as working around stored energy is inherently dangerous and I can only give you the information and you decide for yourself.