Download ASA 5500-X Software from Cisco or use
Note: if you DO NOT have a valid Cisco account you can download it here
Now that we have the software load up ASDM and drop the file inside the ASA Flash.
Now that we have the software we need to activate it on the asa, run the following commands or just use ASDM
The CLI for the commands is here.
en conf t rest api image boot:/filenamehere rest-api agent
Test it out by browsing to the API page for objects.