It is possible, but I am not aware of many adult learners who have achieved this (in spite of watching many YouTube videos about language learning).
The example that always come to mind is Dashan or Mark Rowswell, a Canadian who started learning Chinese at university and became so good at it that he could do xiangsheng or "crosstalk", a Chinese type of stand-up comedy. The funny thing is that Mark Roswell sometimes meets Chinese people who say that his Chinese is not as good as Dashan's, while others say his Chinese is better than Dashan's. (See for example the interview The Most Famous Foreigner in China on YouTube.)
Liam Bates, who has worked as a television host in China, may be another example. (I can't judge his accent; check for example 跟着老外回家乡：第一集 on YouTube.)
Danielle Swisher's guest post How To Speak A Foreign Language Without An Accent on the Mezzofanti Guild describes her experience of getting rid of her American accent in French. She made the following changes in practicing her French:
- She listened more closely to the people she spoke with, to people on radio stations and on tv and to her teachers. She also mimicked native speakers: not only the sounds they made but also how they moved their mouth and their body language.
- She watched native speakers in action. This also included watching how the greeted and parted from each other, their facial expressions and body language.
- Finally, she "practiced using these techniques, sometimes for hours in front of the mirror, and/or with a recorder."
The result was that roughly six months later, people in France started to assume that she was a native speaker of French.
So if you already have a "good accent", forget IPA, forget "minimal pairs" (unless your friends tell you that your pronunciation sometimes causes confusion) and start mimicking people and audio recordings.