Preferably, use a perforating wheel to cut,
but in lack of such, you can cut along lines with a scalpel,
taking care to not cut all the way to the edge.
Considering that we were working on a German collection, I had to find a beer accessory. I was lucky to encounter the Hermetus. Flip off, unscrew, seal - it can all be done with the Hermetus. Slide it over the bottle opening. It stays put, sealing your bottle tight. I actually used it to seal a bottle of Prosecco, and it worked great. Nifty instructional graphics on the top. Drink beer. Drink booze.