How to get E4 Orion CSS Preference editor installed on Eclipse?

Question

Today I got annoyed once again with the fact that starting Eclipse Luna, the Most Recent Used Tab option became disabled by default. I googled for the problem and found the question Eclipse tabs repositionning and Retain previous open file(..) that both suggest to re-activate it either by switching to classic theme in preferences or to edit the CSS of Eclipse.

But switching to classic theme does not seem to work in my case, maybe because I am using STS or a too recent version of Eclipse, I don't know. So I decided to try the second option. Followed the relevant link to Eclipse wiki and begun to struggle:

The Url they give for the update site does not work in my Eclipse:
http://download.eclipse.org/e4/updates/0.16/. I tried to use the upper version
http://download.eclipse.org/e4/updates/0.17/, which works sometimes and sometimes not but the E4 Orion CSS Preference Editor does not seem to be available in the 0.17 version.

So how do I retrieve the correct url for the package?

Answer 1

The answer was in Eclipse E4 wiki: Go to the E4 download page, find the link appropriate for the repository you want. Here this is the 0.16 Stable build that we want. At the bottom right of that page you will find the online p2 repo link, which is the URL I was looking for:

http://download.eclipse.org/e4/downloads/drops/S-0.16-201408072200/repository

I pasted above the corresponding URL, but don't click on it you will get an error. Actually it is meant to be copy-pasted to the eclipse "install new software.." panel:

Proceed to the installation as usual and you will finally be able to edit your CSS like in the following screen. Don't forget to restart Eclipse once again to make it take the CSS change into account.

Hope this helps someone else. The whole thing is quite simple, but since Eclipse is soooooo loooooooooonnnnnnng before telling you it can't resolve a repo, it took me quite some time to figure out how it goes.