Just don't install all the updates. The Security Update and Quicktime update are no-no's. Most of the rest is ok I believe. (Don't take my word on that though)

Anyhow, updating iMovie through the updater worked for me. Didn't need to patch the cpuids or anything. Try it, or backup to a time machine drive and try it. That way if it screws up, it's an easy recovery.

3.93gb for mine as well.