Using TortoiseSVN, I need to take changes I've done in a branch and then merge them with trunk.
I am the only developer on this project, so I know trunk hasn't changed. I am learning SVN so that eventually my team can use it.
Basically, I want my trunk to look exactly like the branch.
In pre-svn world, I would just copy the files in my branch folder, delete the files in the trunk folder, and then copy branch into trunk.
In TortoiseSVN, I've tried Reintegrate a branch, Merge a range of revisions, and Merge two different trees. Nothing seems to actually change trunk. I've also tried branching on top of the trunk. This gives me an error, saying that the trunk already exists.
In your case:
In a team environment I would suggest that you first merge the latest modifications from the trunk in your branch, make sure that everything compiles and works, then do the above steps (which will be trivial since you've already tested the changes).
Update
In step 5, I mention killing the branch. That's because once a branch from a feature is in the trunk, it should be considered as part of the trunk. In that case the branch should be killed so that no one keeps working on it. If major modifications are needed for that feature, you should create a new branch for that.
The only branches that I don't kill are maintenance and release branches, unless a particular release is no longer supported.
No matter what, you always have access to every revision so killing a branch is only used to prevent other developers from developing on a dead branch.