If you were asking how to destroy a grand piano and rebuild it as an upright, I could give you a lot of suggestions (actually I have already done so in my DIY hybrid series of posts). With this speakers, I can only point you out to the videos already mentioned, since that is what I did.
nicknameTaken Also, can the foam be cut in a living room, is it potentially toxic, do I have to wear special masks… ?
Well, everything is toxic, and everything is not. You can get seriously ill for drinking too much water, and you can literally die in a few hours for eating too much kitchen salt. It's all about quantity and time (for water it's about 5-6 gallons, IIRC, for salt is about half a typical package). That's a funny way to say that I don't really know for sure, however since it's a pretty common product used in constructions, it must be at least decently safe if not totally safe. People often complain about other things for this product, but I've never heard it as toxic, even mildly so. It does not make any dust when cut with a box cutter which is what I used and what those videos suggest. It's really simple: buy, cut (unless you buy already the dimension you want, which is available), glue the exciter, with the provided double tape. For some tests, I first held them by hand, and then taped with normal tape. Some exciter already have the push connector for the speaker wire, so you don't even have to worry about soldering or crimping.
Again, those videos describe all I know better than I could in words.
