Update Read Only Property

I have a sharepoint document lirbary which has a custom content type as the default content type. The content type has a number of fields which are defined as read only to prevent users from being able to update them (but they can still be updated via code)

When I try to interact with the document through K2, using a Sharepoint Document activity, the read only properties are not displayed, so I am unable to update them.

Can anyone tell me how I am able to update read only properties of a document in a sharepoint document library using K2??

It would seem to me that K2 should be able to do this, as read only just means that it can't be updated through the GUI.

Thanks in advance for any assistance!!