if you're lazy like me do thissorry, but how do i create an empty bin?
create a text file name it whatever
put "amiitool -d -k retail.bin -i encrypted.bin -o decrypted.bin" on the text file and save
change the extension of the text file from .txt to .bat
now just name your encrypted amiibo bin to encrypted.bin and create an empty bin file named decrypted.bin and just run your bat file every time you want to decrypt your encrypted amiibo and transfer it to your empty bin file