How can i edit the pages and java files in an adf EAR file in Jdev 12c

Hi Team,

I have an EAR file in hand. Now i need to make some changes in the application.

Changes are given below,

1) Add a new attribute from DB to EO and VO, from this attribute i need to create a cascaded LOV depends on an existing LOV in the jsff page .

2) Add a button to show a popup with a table and a button inside it. I need to delete a row in the table while clicking on the button in the popup.

3) Upload a file to insert data into a table.

4) Add a button in the page to create an order which should get saved in the DB (via AMIMPL)