With a moderate level of mechanical ablility the NOS 5180 system is easy to install(I installed mine myself 2 years ago) and I bet that BTR has good instructions for the rest of the installation, i'd do it myself as a weekend project so as not to be rushed..
Read your instructions carefully,take your time,use teflon tape and keep the connections clean. Test the solenoids with the propane and NOS valves shut off.. Open up the valves and then use soapy water to look for leaks.
Then take her out and get a feel for that extra raw power. ((Word to the wise))anything less than 3rd gear when activating you'll bang the rev limiter before you can get out of it
That's actually a bad thing because the NOS is spraying into a dry motor when that happens :-( Also, Be sure not to spray the NOS/Propane into your motor when not running over 3000 rpm..
The instructions for wiring hookup that came with my kit were for the RT10 and did not match the wiring on my GTS although i'm sure Tom has remedied that for his customers.. Good Luck!!