Go to Settings > Social Accounts, click "Disconnect" next to the account, then click "Disconnect" again to confirm. It's disconnected straight away and we stop receiving data from it.
Before you disconnect:
If you're in a campaign on that network, your posts won't be picked up automatically until you reconnect.
You can't apply to campaigns on a network that isn't connected.
The more accounts you connect, the more campaigns you can qualify for.
Switching Instagram accounts? See How do I connect another Instagram account?