Granted, the error message is not quite describing the problem correctly. You have changed all of the back slashes before the double quotes to forward slashes. I don’t think this is what you were asked to do. You should do two things:
change the outer quotes to single quotes (this means change the quotes around the entire string from double to single quotes, which you have done).
remove the escape characters (the escape character is the backslash, you want to remove them)