I think the Trump base knows all that (about Trump's, ah, questionable ethics and, um, distance from the truth and so on), and they don't care, because Trump's appeal was never that he was ethical, or that he was telling the truth. His appeal was that he would do what they thought needed done. And he has more or less done that.
They didn't think that open borders were a good idea. Trump has pushed fairly hard to close them.
They didn't think that shipping jobs to China was a good idea. Trump not only paid lip service to stopping it, he put tariffs on China.
And so on.
Now, if you want to get rid of Trump, you almost certainly have to appeal to those people. You aren't going to do it by telling them how stupid they are, or how racist they are. You aren't even going to do it by telling them how much of a liar Trump is.
You have to do it like this: "You're worried about jobs going to China? Yeah, we understand. That's a real concern. And you don't just want a welfare check when the factory closed, you want another job. Here's what we're going to do about that, and here's why it's better than what Trump is doing." And you need to be right - your approach has to be beter than Trump's, and they have to see yours as better.
You can't get rid of Trump by looking at half the country as backward hicks who just need to be stomped into political oblivion. You have to care about their problems, and you have to help with their problems. Then you can make a dent in Trump's base.