How to change URL structure without breaking the links in Wordpress?

Hi all,
I would like to change my permalinks (URL) structure without breaking all the links to my site. The reason why I need this change is to be eligible for Google News, for which there are specific requirements.

The problem is that once I change them in WordPress, it changes the structure of all of my current posts and thus breaks all inbound links.

1. Is there a way to change the URL structure only for new posts?
2. Is there a script or something that can redirect all the old links to the new URLs?

Currently, the URL structure is the following:
www.website.com/%postname%/

It should transfomr into the following:
www.website.com/%postname%-%post_id%/

Thanks in advance!

I did it with one plugin, but it was all done manually. How many "old" posts do you have? I am not sure if there is anything like what you are looking for. Only make for each post manual redirection, what can be done pretty fast in fact even for many articles.

yep find a Redirection plugin....
if you have only a few urls then you can do it manually,
but with a plugin for lots is better

Well I have more than 5k posts. So I have to use tools that automate the process. Any recommended plugins?