Ok, But you sent the role assignment to a user, I want a role to remove from the user. How can I do that ??

Hi, I'm not sure but this may help you Role Assignment

POST(/druid-ext/basic-security/authorization/db/{authorizerName}/users/{userName}/roles/{roleName})

Assign role {roleName} to user {userName}.

DELETE(/druid-ext/basic-security/authorization/db/{authorizerName}/users/{userName}/roles/{roleName})

Unassign role {roleName} from user {userName}

POST(/druid-ext/basic-security/authorization/db/{authorizerName}/groupMappings/{groupMappingName}/roles/{roleName})

Assign role {roleName} to group mapping {groupMappingName}.

DELETE(/druid-ext/basic-security/authorization/db/{authorizerName}/groupMappings/{groupMappingName}/roles/{roleName})

Unassign role {roleName} from group mapping {groupMappingName}