How to Install Kernel Source Without Internet on Ubuntu Gnu/Linux Distro
GNU/Linux Ubuntu Kernel Source Offline Installation
Hi! The Tutorial shows you Step-by-step How to Download and Install Linux Image for Ubuntu GNU/Linux Computers.
And the Ubuntu linux-image Package provide the complete Source Code for the Linux Kernel.
Most noteworthy: to achieve this Setup you simply need any Online Computer with a Browser and a USB Stick to Copy the downloaded Package.
But if you dispose of an Android Mobile Phone with Internet Acces, then an Easier Solution should be of using it! See: Internet Connection USB Tethering Guide.