edit php file & install a script in another domain

You will have to do 2 tasks. first is edit a php file displaying invoices in our website in order to display the data as needed, second is install a nulled script i ll provide for another domain. We wan't to modify the [login to view URL] file in order to display the invoices in the new format. Moreover we made some mistakes on many of invoices, instead of giving discounts on Tax free total price, we gave it to the all tax inclusive price. So based on what we actually were paid we wan't to modify the code in order to display automaticaly the good tax price, the corrected discount and the good tax free total price as explained in attached doc. this is a quick modification on a php file, we ll award the project to the fastest and cheapest solution that can do both of the tasks..