I bought these Camera Raw presets, which came in a .zxp file. To install I need to unpack the file and then copy the xmp-files into the right folder. That will be no problem. But I am having problems unpacking the .zxp file. I tried with the suggested Anastasiy's Extension Manager which gives an error. Then I tried ZXPinstaller, which says it's invalid. Does anyone have an idea what I can do?
Please go back to the vendor you bought these presets from and ask for their help on installing the presets. If they can at least help you unpack these, and you have xmps, all you have to do is zip them up and import them into ACR.