I love Thai Law !!
I found the 75% rule....it is on Siam Legal's web site
However, with that said...
Looking at the Condo Act of 2008 it not so clearly states a 50% majority vote AT THE MEETING will suffice in changing the CAM charges.....MAYBE !.....it is very very fuzzy and the law contradicts itself in several places.....could be the translation...could be intentionally vague...could be a lot of things.
There is a ton of discussion on various websites with horror stories about this situation with the Land Office, the Competent Person and the courts.....the uninformed must beware !
But, we must assume the worst and have a plan for the meeting so we are not bowled over.
BG