curl --request DELETE \
  --url https://statsigapi.net/console/v1/holdouts/{id}/overrides \
  --header 'STATSIG-API-KEY: <api-key>'

{
  "passingUserIDs": [
    "remove-passing-user-id"
  ],
  "failingUserIDs": [
    "remove-failing-user-id"
  ]
}