Uwe Brauer:
I followed the discussion in http://meta.wikimedia.org/wiki/Help:External_editors about how to use an external editor, since the perl solution worked once and then refused to work, that is clicking to the editing button did not bring up the editor,
Try visiting a URL like http://en.wikipedia.org/w/index.php?title=Talk:Main_Page&action=edit&...
that is, add &externaledit=true after the &action=edit -- this should tell you if ee.pl is at all being called correctly. Make sure you are editing a wiki you have actually set up ee.ini to work with. Each Wikimedia wiki has its own user account database. The URL also needs to match the URL match listing in ee.ini.
Also try starting ee.pl from the command line to test if the GUI is working. More debugging can be done by feeding it the control files the wiki sends to your browser on the command line.
The bookmarklet does nothing more than generating a URL like this from the page you're looking at, and telling your browser to visit it, so if this doesn't work, neither will the bookmarklet.
However the information is not very detailed. What shall I do with this small script save it as a file or what?
Create a new bookmark/favorite in your browser and copy the JavaScript snippet exactly as it is into the field where you would normally write the URL of a webpage you want to visit. Visit the bookmark/favorite whenever you want to use the external editor. But again, make sure ee.pl is set up correctly first, or you will have to debug two things at the same time.
I've tried to expand the instructions on Meta with the above; let me know if it makes sense to you.
Best,
Erik