How to Disassociate Entities in a Workflow that are related on a N:N basis

Hello

I've created a Workflow that blanks out the postal address, email address and telephone number fields on the Contact entity when another field (Deceased) on the same entity is set to Yes. This works perfectly.

However, we have another entity called Communication Preferences which is linked to Contacts via an N:N Relationship. Any Communication Preferences against a record need to be Disassociated when the Deceased field is set to Yes, but so far I'm unable to work out how to Disassociate items in a Worfklow.

If anyone could please help me out it would be much appreciated.

Many thanks
Jon