If you change job or have a promotion at your current employer to update your Linkedin profile to put in your new title or new employer
Go to profile > edit profile
Click on EDIT next to Current

This will take you to this page. Change the details that you require to

When you’re finished click update
You can also update your profile, if or when you require due to a change in circumstances.
Summary – précis of your job an your specialities
Experience – Your current job and any company’s you have worked for previously and in what capacity
Education – the school, college or and university you attended, what dates you attended, what qualifications you achieved and what groups or societies you were a member of.
Additional information – This area allow you to input your company website or website if you have more than one, facebook address for your profile or facebook address for your company fans page.
Rss feed – if you have a blog with an RSS feed then you can put the address of your blog feed here
Interests – self explanatory
Groups and associations – this is for official bodies that you are member of
Honors and awards – again self explanatory
Once you are happy with your changes click save changes