I used something called citristrip home varnish stripper with great success. Not sure if you can get it in your country but it’s not nearly as toxic as lacquer thinner and can be used in doors. Get the spray version, spray the mask and leave it on for 30 minutes to an hour then scrub away. Reapply if needed and repeat.
Hmmm, any “paint and varnish stripper” should be good maybe not the same exact brand. I prefer stuff that works indoors as I don’t have a garage… lol, lacquer thinner will ofcourse work but it can be pretty harsh.
Soak the mask in warm soapy water overnight. That will loosen the paint some. Then use a stiff bristle brush and more warm soapy water and a lot of scrubing. Take your time, work firmly enough to remove the paint but be careful not to rip the latex. This will work. It takes quite a bit of time but you are assured of not damaging the latex and it is non toxic.
Then you should watch multiple tutorials on YouTube showing you how to prepare and paint a mask. You can do this without an airbrush. But it takes time and a lot of trial and error.
Tried another Method after watching many Videos and after all these good comments here! RESULT (not finished yet, some paint from TOTS came off and i need to add it with latex):
Looking much better. I noticed the kills masks are a lot harder to get the detail in compared to the 2018 mask as most of the cracks are already filled in on those. I myself haven’t gotten the hang of the kills masks. I think they’re much more difficult to rehaul compared to the 2018s.
Looking really good. I think you should maybe stuff it with some plastic bags for the proper shape when on display. Some hairstyling can also change the whole look of the mask.