Today I tried to order a Öhlins fork cartridge set only to learn that Öhlins will only have them available mid to late May. No joy then, so instead, I installed a low tone horn

(from a BMW car, off the auction site). It doesn't sound like a scooter beep or like a PC motherboard piezzo when Windows explodes, it sounds like a horn proper.
I had to lift the tank just a bit to insert the bigger horn but to remove the original one, that is not needed, I managed to do it with a 13mm socket+1/4 cardan+200mm extension+100mm extension+1/4 ratchet. It works from the left side of the bike, behind the frame. It's a knuckle scratcher but doable.
To lift the front of the tank, I didn't need to remove the seat support brackets as I just lifted it about 5 cm, just enough to squeeze the bigger horn through. I put a 5mm-thick strip of black foam tape between the steering head and the horn itself, putting some pressure and preventing the horn from scuffing the paint.
I'm really disappointed with the Öhlins issue, just today I received the last tool I needed to that job, I've been collecting them for the last few months getting ready for this and now: not available.
It may have to do with the fact they are busy with a recall, building a few thousand front dampers for their Porsche 996/997 Turbo/Carrera 4/4S aftermarket coilover kit. A few of the original versions sheared off on the top mount interface. I know this because I'm affected and am waiting on those replacements for my car.