how to change password

We have change administrator password. How can i change the sql server job password, so that the maintain plan work fine as before. Thanks.Modify the login used by the SQL Server Agent service.|||Thank you very much! So i just right click the sql server agent then change password there.|||Right-click the service, open up properties, and go to the Logon tab. That is the most likely culprit.|||i am a little bit confuse. What i did is go to sql server enterprise manager, the expand the management, then right click the sql server agent to open properties. then change the password there. But i am sure what service you got, where can i find it? Did i did something wrong. Can you give me more detail about changing the password? Thank you very much!