configure apache for large file size upload through script

I recently hired a dedicated server and uploaded my web files to it. I am using a php script to upload a few large csv files of up to 120mb in size. I have changed the [login to view URL] settings to allow such large files to be uploaded using php but the problem is in the apache configuration. I need someone to configure the apache server to allow upload/process of files up to 120 mb. After a few seconds of upload I get the following error: Request Entity Too Large The requested resource /admin/[login to view URL] does not allow request data with GET requests, or the amount of data provided in the request exceeds the capacity limit. Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.