Like Bitt said, you can download the v300 tarball and patch up from there. Download v300 and all the v300+ patches, then untar v300 into a directory. Change into that directory and run the command:

zcat `ls /path/to/patches/hijack*patch.gz | sort -n` | patch -p1

to patch your v300 tree up to the current version. Now you can continue from step 7 in Shonky's instructions on that post you linked to.