You have to get in touch with the accent whenever you can. Watch interviews (if you have BBC on cable TV you can take advantage of both, having the news and the accent as well.)
There are documentaries on line, you can speak to natives, well...there are many possibilities. Let´s wait for more suggestions.
Ah, there are sites and dictionaries online in which you can see how words are pronounced.
Depending on your level and English experience you can use the international phonetical alphabet.http://www.oxfordlearnersdictionaries.c ... on_english