This is not going to be easy, depending on which mods you'll be translating.
Generally, there is not one place where you'll be editing and then you're done. You basically need to go through every form, cell, dialogue topic, quest etc. that has a name that is shown on screen (in contrast to just internal identifications) and edit that.
It might probably be best not to use the CK, as you can't load only a plugin without its masters (skyrim.esm) but some external tool like TESVSnip. (SkyEdit would work, too, but currently is too limited in its capabilities - no dialogue editing, for example.)
So open the plugin in TESVSnip and click through all the entries. What you usually want to edit are the FULL subrecords:
Load the plugin.
Select the record in the upper left.
In the lower left window, select the subrecord containing a string, i.e. the FULL subrecord, and in the button bar of that window, click "Edit Subrecord". Translate and save, and continue with the next.
I'm not sure if you get everything in this way, and you should really only translate screen text and avoid changing internal identifiers at all cost, but that's the general direction.
P.S. Wenn was unklar ist, kannst du auch gerne eine PM auf Deutsch schreiben, auch wenn ich fürchte, da? das, wie geschrieben, keine triviale Sache ist. Vor allem zu erkennen, welche Eintr?ge man ?ndern kann bzw. mu? und welche man tunlichst in Ruhe lassen sollte, ist wichtig.
