I have no idea how to install on Linux, or update...or should I just ask on the links you provided of Linux forums?
it is best to ask on /r/tails those guys are more familiar with both linux and specifically Tails than me
but you can install anything as you install it on any other Debian based linux. you just have to take additional steps for setting up the persistence volume.
read these to get you started:
https://tails.boum.org/doc/first_steps/persistence/configure/index.en.html#additional_software
https://tails.boum.org/doc/advanced_topics/additional_software/index.en.html