How did you unlearn bad habits developed due to terrible language education at school?

The English education in Korea, public or private, is hot garbage that does everything it can to make the learner NOT speak English and NEVER enjoy speaking it. My wife is also a victim of that ""education"", and now struggles a lot to pick up real English spoken in England.

On top of her perceiving English as a torture source, I've also noticed that all the horrible language learning habits (always thinking strictly in Korean, putting too much effort to remember the name of the grammar rules rather than the rules themselves, etc) she unwillingly developed throughout the school years in Korea are hindering her learning severely.

Thought I'd ask for some advice from people who started their 'real' English learning from similar backgrounds. What are some effective methods my wife can take to unlearn her bad habits and shift the way she perceives English language?