You're asking a pretty complex question here! But heres my take: Read and watch the English News, for example BBC. Surround yourself with the language, even if it is at first overwhelming, you will force your brain to study the language by doing this. Listen carefully, concentrate. Write and converse with native speakers that give feedback to correct mistakes. Read alot, listen alot, write alot yourself, avoid mistakes, do all of this more or less regularly. Done.

In order to become fluent in a language you need to practise speaking to someone every day.It can also help to listen to a lot of English- for example news broadcasts,songs and so on.But the main thing is to practise as much as possible with another speaker.