It took me a long time to move my accent into a more hard-to-trace area of “Immigrant” and “Brooklyn”. I now sound like an exotic native with a colorful background. It almost begs for the question, “Wow, where are you from?” Sometimes, I can get away with just saying, “Brooklyn”.
In my case, I used my musical ear to listen to spoken language and treat it like a song. When I spoke, I sang their song instead of my own. It also helped me listen to the radio all the time. When I heard a phrase that I thought I could use in a conversation, I would repeat it out loud. I repeated it until I was sure it sounded like the person on the radio and not like my old self. Still, nothing changed much until I physically moved away from Brooklyn. Once I was safely in a new place, everyone spoke differently. In a matter of six weeks, my accent began to dissolve. I worked hard at it but made little progress while actively conversing with Yiddish speakers from my past.