Conversion of Xpath assertions from Json to Plist

We have current framework which will handle json responses (accept=application/json).we have asserted against the response by Xpath and groovy script.
Now the response has been changed from json to plist(accept=text/x-xml-plist).

So the current json Xpaths and groovy script will not hold good.

We have around 3000 test cases and more than 100 suites.
So converting all assertions will take lot of manual effort and time .

Is there any way to the existing Xpaths and groovy assertions to convert to plist.