Setting the PHP settings such as upload_max_filesize is easily handled through the multi php.ini editor. Simply log in to your Cpanel account and search for the multiphp ini editor. Next in order to modify the settings select the location. In the case of an installed WordPress site, you will want to select the location of that site. It should be in the drop-down menu.
Next, you will be able to modify the settings as you wish. Basic mode works well for simple upload settings. Advanced mode is for those who know what they are doing. Remember to press apply and your new settings should be updated.
These are common settings used for increasing PHP upload limits:
These settings should allow for uploads up to 128M on the server.