Edit config.h and make any changes that you want. The most important option in this file is the selection of your operating system. Only one system type should be defined. Copy the appropriate make file to Makefile. Look over the Makefile to see if there is anything you want to change.
Type make to build the program.
You should not get any warnings or errors. You should now have the executable files maketcp, makeip, makeudp, makeeth, makearp, sendeth, and sendpacket. Install these wherever you want. The contrib directory contains some simple scripts which can be used as examples when creating your own packet generation routines. This packet would be used as input to the makeip program.