How to manually update Entity framework Code first model so that it updates a database (with a new column)?

can somebody tell me how I can add a data member (col) to my mvc3 model (class) and have it update the database without having to generate everything from scratch? I’m working from code first. When I change my model then run my project I get an error stating that model has changed. Any clean and easy way to synch creating a new col/data mamber with the db/model?