There is no easy way of doing anything in the world!! But you can improve your english by reading lots and lots of books....am not talking about comic books ...but other books, be it encyclopedia or any other novels....don't read Sydney Sheldon's books but otherwise you can read other good novels by other authors. Also practice grammar at least for 10 minutes everyday. Always keep the dictionary with you so that whenever you read books and come across some really difficult words then you can immediately check out the meanings. Do not leave it do it after sometime because you never will. And also that way you will not only learn new words, it will also help in improving your vocabulary and communication skills.
Hope I helped u....and last but not the least, first always understand and then only learn. Never cram. Don't do ratta!! Make the dictionary your Bible or Gita.