You can change them for any specific account from cPanel using below mentioned steps:

1. Login to the cPanel of the account.

2. Go to 'Select PHP Version' option.

3. Select 'PHP 5.3' if the current version is set to 'native PHP 5.3' and click on Apply button and then 'Save' at the bottom of the page.

4. Go to 'Switch to PHP Settings' link to top right corner.

5. From there you can change value of any variable and by clicking 'Save' button it will be applied on the account.