Read old posts written by Bejing101 and you will learn a thing o
You can hire a private tutor. You can attend classes at community college (very cheap). You can go to local church every Sunday. You can go to your HR and ask for advice. You can do a lot of things to improve your English.
The key is to motivate yourself, make a plan and stick to it! Heck, you can force your best friend talk to you in English everyday!
One muggle