What version is installed?
The installed version is 4.6.5-4pclos2011
In that case, mark them for removal, make a note of any additional packages removed (if it's just a few), upgrade and then install the newer equivalents. If removing one of these wants to take out everything including the kitchen sink stop and come back for more advice.
However, it's probably best to answer O-P's question first, and muungwana's tip is also good for getting further info.
It seems I can remove them without losing everything else. But how should I proceed?
Mark all packages to be uninstalled, apply, apply?
I have opened Synaptic and marked the packages to be uninstalled. I have not pressed "Reload". Now, if I hit "mark all upgrades" it will show all the packages to be uninstalled and upgraded.
Try to update from the terminal to give more information on what is going on.
Open the terminal.
Log in as root.
run the following two commands and post the output of the last one
you log in to root's terminal by typing "su" and then pressing "enter" and then entering root's password followed by pressing "enter" again
[root@localhost 2] ~ > apt-get dist-upgrade
Lese Paketlisten... Fertig
Erzeuge Abhängigkeitsbaum... Fertig
Berechne Upgrade... Gescheitert
Die folgenden Pakete besitzen unerfülte Abhängigkeiten:
[i]"The following packages have unresolved dependencies":[/i]
kde-utils-ark: Obsoletes: kdeutils4-ark (<= 4.6.5)
kde-utils-filelight: Obsoletes: kdeutils4-filelight (<= 4.6.5)
kde-utils-kcharselect: Obsoletes: kdeutils4-kcharselect (<= 4.6.5)
kde-utils-kdf: Obsoletes: kdeutils4-kdf (<= 4.6.5)
kde-utils-kfloppy: Obsoletes: kdeutils4-kfloppy (<= 4.6.5)
kde-utils-kgpg: Obsoletes: kdeutils4-kgpg (<= 4.6.5)
kde-utils-kwallet: Obsoletes: kdeutils4-kwallet (<= 4.6.5)
kdenetwork-kppp-provider: Obsoletes: kdenetwork4-kppp-provider (<= 4.6.5)
E: Fehler, pkgProblemResolver::Resolve erzeugte Fehler, dies könnte von zurückgehaltenen Paketen verursacht worden sein.
Resolve erzeugte Fehler, dies könnte von zurückgehaltenen Paketen verursacht worden sein. "Resolve created errors, this could be caused by held back packages."
Is there a solution?