Generally speaking you compile from source. And hope you've got new enough
libraries on your system to support the newer version. (It's probably
possible to have different versions of libraries on your system too but
that's beyond my abilities.)
There might be a precompiled version somewhere. And it might or might not
contain non-free software. So go to the home page and see what they say about
the subject.
Hardware often needs firmware and a driver to work. Many pieces of hardware
don't work on Trisquel at all because either is missing. Performance and
features are entirely dependent on the firmware+driver.
