567358 php script to change file permissions and edit file

Hi, I need a script the will change file permissions, change a line of code in the file, then change the file permission again. Specifically, I need the script to do the following: Change the file permissions from 444 to 644 on the following files: public_html/includes/[login to view URL] public_html/adminarea/includes/[login to view URL] In those two files I need the following lines changed from: define('SQL_CACHE_METHOD', 'database'); to define('SQL_CACHE_METHOD', 'none'); Then I need the file permissions changed back to 444 on both of the files. You will need to provide the script as a single php file. I will upload this file to each of my accounts and when the script is loaded, it will perform the above functions.