Many ways, and not one definite answer.
What's known it can take a bit of time, preparation and effort. It can be done alone and the internet resources are very helpful but taking the right mentor (I recommend it over courses that are more theoretical and general) can shorten the time to the Junior position.

I've seen it with my mentees in live, with the right direction from someone who been there (in my case over 100 product interviews, over 30 home tasks) and developed some methods and the right materials it can be done.

Feel free to consult