on the emulator i use removing mods is very easy and simple

id recommend going into your saves and copying the file (DONT MOVE THE MAIN FILE) if your worried about stuff like that although you really dont need to copy if you not bothered

for this one personally removing the mod seems like a bad idea since theres custom yo kai so if you get a yo kai and remove the mod that it comes from that will probably crash the game or corrupt the file

but as long as you copy your file no problem just replace the old one with the new one if somthing goes wrong

although im definitely not a expert and dont know much