They could simply declare the diplomatic staff persona non-grata and revoke their diplomatic status. They'd have to leave the country. They could even cancel th

They could simply declare the diplomatic staff persona non-grata and revoke their diplomatic status. They'd have to leave the country. They could even cancel the diplomatic status of the embassy. That wouldn't have immediate effect and the Ecuadorians would have treaty guaranteed rights to clear out their effects but it would eventually lead to a moment where Assange is inside a building emptied of diplomats which ceases to be an embassy at some defined hour.