If you speak clearly, there should normally be no need to get rid of a foreign accent - it's part of your identity. However, if you do have reasons why you want to sound more like a native speaker, you can help yourself by studying the phonemic system. There are 44 individual sounds in English, and to get a standard pronunciation (often called Received Pronunciation) you need to be able to reproduce all of them. it's not as hard as it sounds because most of them are common to all languages - you will probably find that it's just a few sounds that give you trouble, usually mainly vowels.

There are plenty of free pronunciation exercises online, but for intensive practice a book is a good idea. I would recommend something like Ship or Sheep or the Headway pronunciation series. Record yourself so you can compare your accent with the ones you hear on the CDs. Then when you feel you know English pronunciation quite well, you should probably try and get a few lessons with a native speaker, preferably a qualified teacher of English as a Foreign Language.