Ok, he need to become a trimix diver himself at first. For normoxic trimix instructor you need to be full trimix diver.
Then you can start the first techlevel instructor course, most times it is adv. nitrox. If you have teached that X times, you can do the next level instructor course.
Of course you need to gain experience yourself first. I know instructors who did the normoxic instructor course in conjunction with the full trimix user level. I don’t know if this is the right way to do, as you really need to know what you are doing.
The question if you want to teach 60m trimix is first: do you feel comfortable at that depth and able to do such dives solo? If not, don’t start teaching this level.
Full trimix level, same. And if standards mostly state the minimum depth must be around 75m, do you like to do this course with an instructor who never went deeper? You certify to 100m, and the dives are really more complex at 100m then at 75m.
How long does this take? All depends on what you really want. I have a full time job, but still do 200-250 dives a year. I did all my user levels techdiving in 6 months, only 2 years after starting diving. But I was passionated. My adv. Nitrox was finished at 1 april, 6 april I started cave, 1 week later I was full cave, dive 390. June I did normoxic and October I did full trimix and did my first 100m dive. That was dive 521. My first dive was in august 2 years earlier.
But I still was no instructor. I did this later, around 900 dives. The first ‘tech’ level I did was adv. Rec. trimix instructor. Then had to certify X people, then did the next level, etc. It is quite expensive and you don’t earn it back, but I liked it to do it. Normoxic is done quite a lot, full trimix not. Most people won’t go so deep and helium is expensive. Even with ccr, most people stay in normoxic levels.
But it is possible to become techinstructor if you really want. I wanted it and I live 12 hours from caves and the nearest full trimix lake is 1000 km driving. But don't expect you earn your investment back. It is not only become instructor, but also stay current. To do 20 or 25 dives on the highest level each year again, you need money and time.
