Step 1) Release the metal collar by prizing its edges out and up from the plastic part. Then slide the metal collar up the clear tube exposing the plastic moulded tube release tabs.

Step 2) While holding the base with both hands, depress the 2 moulded tabs while lifting upwards on the seed tube to release it.

Step 3) Photo showing tube separate from the base.

Step 4) Use a safe, non-toxic cleaner to soak the seed tube.

Step 5) Use a nylon bristle brush to scrub the inside of the seed tube 

Step 6) Use soft brushes or similar to gently remove debris from the base, run base under hot water if that helps break seed up.