Visual Studio 2008: Updating current code with changes made in previous branch

Our TFS is di开发者_Go百科vided to a "work in progress" directory and several branches of older versions.

We made some major changes to the previous version and now we want to apply these changes to the current version.

Now, the problem is that I don't see how it can be done easily:

I can compare the two versions - but it doesn't let me copy the changes or check out the relevant files.

I see the changes made in each changeset - but it doesn't give me an easy way to copy the changes to the relevant files in the "work in progress" version.

If the changes were done in branches you should have a merge option no?