Change depth in existing SVN working copy without redownloading

Question

I have a working copy of an entire SVN repository, but I want to change it into a sparse working copy because of disk space issues.

One way to do this would be:

Answer 1

I don't know why people are doing things the hard way in the other answers.

Since Subversion 1.6 it's possible to simply do svn update --set-depth exclude