This general agreement will not change. Edit, update or cancel part or all of that, unless there is a written document which matches the powers to represent both parties have signed.
In general terms, this is not changed, modified or canceled in whole or in part. Unless there is a written document synchronization. The authorized representatives of both parties have signed it.
General agreement on this issue will not change, edit or cancel all or partial Unless a document matching in writing. Which authority was instead of the two sides signed.