Updating your rails application?

How can I update my rails application to work with the current release of rails? For example, I had rails 0.9 and created an application. I installed the will paginate plugin and now the application can't run. I upgraded everything and created a new test application, installed the plugin and it works. However, my old application doesn't work.

So basically, what I'm getting at is, each time a new version of rails comes out, how can I update my application so that it'll reflect the current release of rails? Thanks!

Just figured it out...for anyone else who was wondering this, it seems you replace the config directory with the newest version (careful not to overwrite database.yml).

This works great if you use some sort of version control like subversion. I let the update overwrite all files it wants to then I revert the unwanted changes.