Download the sources from the Linux Downloads Forum. Download all files supplied, as all patches are required for Linux to run on your development system. (eg. Linux-2.4.x.tar.gz, patch-2.4.x-rmk?.gz, diff-2.4.x-rmk?-np?.gz & diff-2.4.x-rmk?-np?-ads?.gz).
Make sure you read the installation instructions included with the source files. The order you apply the patches is critical.