[Trisquel-users] Re : I ask this, but how do you downgrade the linux libre 4.5 to 4.2 in libreboot?

[lcerf]

Install a "linux-image-*-lts-wily" package (in Trisquel's repository) and  
remove the 4.5 kernel (from the package manager too). GRUB's configuration  
will be automatically updated to default to the latest kernel, which becomes  
version 4.2 (assuming you have not installed another more recent kernel).