Dealing with KM resources - Return

Hi guru's,

I come back with the following of another post : http://scn.sap.com/thread/3256471

The context:

One jave webdynpro which must :

• check the existence of a document
• if the document does'nt exist, the WD user must upload it
• the upload action itself must
  • set a property to the document
  • set a permission on the document.

I'm now stucked on the last step : setting permissions on the resource itself.

My WD User has Read/Write on the folder where the resource is uploaded through a role.

On the resource itself, the WD User must set a new permission for himself (Read/write) AND delete the permission for the role that gave him thoses rights.

Is this possible? For now, i'm stucked with things as "Access Denied"...

What would be the correct approach?

Regards,

Michaël