For the larger ones from europe you can get a new capping bell that just swaps out with the one you have and some 29 mm caps. Total cost about 7 bucks. If you want to use something other than caps you'll need both corks and cages. The belgian breweries use the belgian corks with cages for both "belgian" and champagne bottles. This will require a corker and you can find those instructions by searching the forum or youtube. If you don't want to use a corker then the plastic champagne stoppers are your best bet. I've seen some folks say that you can do this with a #9 wine cork, but I've never tried. The #9 is a few mm thinner than the belgian corks and may not seal off the pressure you need. Whatever way you go you'll either need to use a cage, or cap on top the way cantillon does but this would then still require a 29 mm capper. Corks alone would get pushed out of the bottle once carbed.