I think it’s relatively easy to ‘polish off’ an American accent — no offense intended, I’m American. But we drop the ‘g’s at the end of infinitives and say walkin’ and talkin’ rather than walking and talking. Adding ‘g’s to our words would polish off or maybe polish up an accent.

We use ‘d’ in words that have ‘t’ — say, Peter, which is pronounced ‘Peder’. Any American would sound strange or possibly British if they’d pronounce it as ‘Peter’ instead. We also pronounce the words medal and metal the same.

And if anyone would drop the gonna and instead say ‘going to’ it would polish up if not off the accent.

But the person who posed this question doesn’t say what their first language is or what kind of an accent they have that they’d like to alter.