Deploying changes to production using Eclipse IDE

Hi,

I want to deploy my changes to production from sandbox. Here is wat I am doing right now.
1. I imported sandbox code in Eclipse IDE.
2. Created some apex class and tested it on sandbox salesforce. (while saving I used right click -> save to server option)
3. To deploy chnages to production (write click on file -> deploy to server)
4. I entered user name, password and security token
5. Its givin me error for two class files which I never modified and those files exist on production server (some syntax error in those files) and I really can not modify those file

How I can deploy my changes in production. Can anyone please help me with this ? Any help in this regards will be appreciated.

Thanks,
Abhishek