It is about time that google starts to translate weapon and ammo terminology propperly.
Here my translation:
For fuzes of older manufacture the following applies: The membrane on the fuze is removed with the help of a screwdriver and the short wooden rod is removed. Then the screw under the (Umbördelung – whatever it is – google translated it as beading distribution

) is loosened by one thread length, the funnel is screwed in and fixed with the screw. The Screw is tightened until it is forced into the metal of the funnel. Then follow the instructions above.
This means that the upper part of the fuze is of two piece construction. Here a pic cut from the same manual.
Bob