To add epic relation link I have used this request and body but I want to remove it using rest API. /rest/greenhopper/1.0/epics/AG-3/add
{"ignoreEpics":true,"issueKeys":["AG-19"]}
This will add epic link relation for AG-3. AG-19 will be added as a epic relation link to AG-3.
Now for same I want to remove AG-19 from AG-3. From UI also, I have to remove it from AG-19.