Can I edit the buttons located the toolbar on above the window?
Edit in what sense? names, icons?
Icons.
Then you need to get the sources, dat and png files, from the SVN (link (http://simutrans.svn.sourceforge.net/viewvc/simutrans/pak64/other/)) modify the png images and using makeobj, recompile them in order to create a new pak file.
The files you need to get from the SVN are wkz_icons.png and new_menus.dat
I forgot to mention that every pakset has its own menus and icons so this is only valid for pak64.
you can create a menubutton pak file and then define this file in menuconf.tab
examples dats
examples lines in menuconf.tab
empty buttons found in the Tikiwiki (http://simutrans-germany.com/wiki/wiki/tiki-index.php?page=de_painter64_HowTo)
Ok thanks