To disable the DocuSign integration:
Open Admin area
Scroll to Integrations
Find the Slack integration click "Configure"
Click "Remove DocuSign integration"
Humaans and DocuSIgn will now be disconnected
After this, the documents will stop syncing into Humaans.
Note, that the documents that were already synced will remain in Humaans.
You can always re-enable the integration by following the Enabling DocuSign integration steps.