update unity editor only

how do i update the unity editor (mono develop) only without downloading the whole new unity version?

whenever i get a message at the start up of unity 4.3 that there is a newer version for unity editor then i click on the update button, i find my self referenced to whole unity 4.3 application download.

Short answer: just download both.

Long answer: I’m not even sure that would work. It’s definitely not recommended or supported, and either way Unity Technologies only offers them as a single unified package.