The code below checks if the given command line argument is a regular file. If it is then it checks if the file is executable. Finally if the file is executable the code removes the execution permission for the owner.

FileCheckPermissionRemove.sh

#!/bin/bash

removeExecutablePermission(){

	if [ -f $1 ]; then
		
		#echo "regular file"		

		if [ -x $1 ]; then
			#echo "remove permission"
			chmod o-x $1
		fi
	fi	

}


removeExecutablePermission "$1"