Babu,
I went through this a moment back and was able to accomplish it through the following :
1 ) Navigate to "Configuration" > "Relationship". Hover of the "i" to get the "Relationship Type" UID :
2 ) Navigate to the Asset's "Relationships" page, selecting the same relationship. Hover over the "i" of a specific relationship to get the individual relationship UID :
3 ) Within "Administration" > "API" navigate to :
DELETE /api/v2/relationships/{intersectTypeUid}
4 ) Add the type UID and individual UID :
5 ) Submit; The team should see a "Success: true" in the response :
Matthew Kennedy