How I can update my s4 from kitkat 4.4.4 to lollipop 5.1

[francezu2015]

Hello guys. I have an s4 mini, model GT-I9195 with android Kitkat 4.4.4, and I want to install cyanogenmod 12 with android 5.1. When I try to install some custom recovery like twrp or Cwm with Odin, I get an error message like: "could not do normal boot". I ve try to root my phone but I have same result. Have someone idea what can I do? I ve tried all known possibilities but every time have same negative result. It s possible to make some boot unlocker?