A more effective way to say, "Sorry, I was wrong" [closed]

I need an expression for the following context: I had been insisting on an issue, (believing in good faith that I was right) but later realized I was just totally wrong.

What is the most effective way to say that I was "wrong" without using this word?

I am not looking for what can be the best attitude but for the best way to excuse myself without admitting I was wrong and without putting the blame on someone else.

You can say:

I stand corrected.

Possibly add an apologetic phrase at the end or the beginning.

You could say it the other way round:

Instead of saying that you were wrong, say that he was right.

Something like:

I thought about it and you were right all along