ANSWER:
If we were to look at a scale of a hundred, what would these things that they say be on such a scale?
You are preoccupied by small and trivial things while neglecting the major issues that need to be addressed!
These people are not ready for changing such things in them as they don’t see anything wrong in it. You should focus on starting with the foundation by inviting them on one to one basis to memorize the Quran, to pray with the congregation, to learn tawheed, a bit about tafseer, seerah and fiqh.
If you manage to get them engaged in such activities, in 6 months time, you will have no problem in advising them and noticing that they accept all what you say.