If you are using the tags, branches and trunk setup in your subversion repository you will eventually need to merge your changes in a branch back into the trunk. This like most things in subversion is relatively easy once you understand the syntax.

The merge command needs two version numbers, these are a range of branch versions that subversion will collect the changes from. Most of the time you will want all changes made on your branch since you created it. On your branch working copy do a svn log and find the first version number right at the bottom and make a note of it.

You now have to svn switch back to your trunk because merge updates a working copy. Now you have a working copy of the trunk you are ready to copy down the changes from the branch.

Now do something like svn merge 16:HEAD http://svn.test.com/branch/

The number 16 will be the first branch version number the you noted down earlier. If you have done everything correctly you should see a list of files that have been updated.