Bad idea. My suggestion is that you file a First Amended Complaint to obviate the necessity for a Demurrer to the original Complaint. This way, the Demurrer which is set for hearing in November automatically becomes moot.
The information presented here is general in nature and is not intended, nor should be construed, as legal advice. This posting does not create any attorney-client relationship with the author (who is only admitted to practice law in the State of California). For specific advice about your particular situation, consult your own attorney.
If a demurrer has been fled I think you must have leave of court in order to file an amended complaint. I believe that only when the defendant has not yet appeared in the case - by answer, demurrer or motion - may plaintiff unilaterally file an amended complaint.
Nonetheless, it is almost axiomatic for a court to grant leave to amend should a demurrer be sustained.