Hi! To undelegate, you can go https://steemworld.org/@blocklab

Under the menutab: Delegations, you see the outgoing leases.
On the right side, you can click on X to cancel

If you like, you can keep the steempower in your wallet and follow the curation trail of @steemingcurators on https://steemauto.com.

Check our recent posts how to join!