not hard, it's just one of those measure 10 times cut once deals. there are threads on the FE forum where I detailed the install, as well as the link in my signature. It is just servo steered, the servo turns a nozzle to direct thrust. Check out the thread though, it's pretty long but I went through everything, from the original install to the 4 versions that followed.
http://www.rcuniverse.com/forum/m_45..._1/key_/tm.htm