Ns2 how to add new mac protocol in ns2

Hi every one , i have an issue with ns2. How can i add new mac protocol. I am try to add TMAC ( timeout mac) i have its tmac.h file also i have its tmac.cc file and also tmac.tcl file but i don't know how to simulate it on ns2,. Also i want to know that the file smac is already present in the ns2 files, how can i simulate it and how can i make changes to the file and then compare it with the original file.