Already found that kickstart file. but that of course is looking at a an iso on CDrom/USB stick for the new OS.
And obviously would have to change the disk target in there (as otherwise would install the new version on the same partition as the curtrent one)
So I would need to edit that file (and some help pointers as to which bits would be apreciated, as looking in my file I actually nowhere see a reference to the where the iso image is, nor the actuall partition the new OS will go to (but maybe Iḿ misreading some commands).