Update PHP code on open source application

I have an open source application for our document management application (a bit like Microsofts Shared-point) on my web-host and would like to update the coding and the application to include the following: 1) When a user uploads a document or file, an automatic email is sent to the department or specified users, advising them that a document has been uploaded. 2) In the history of a file, it shows who has checked out the file and when they checked out the file. 3) In the history of a file, it shows who has read or viewed a file and when the file was viewed or read. Temporary access to the application directory will be given to the succesful freelancer.