Please try these steps on a couple of DN's first and then apply on rest once you are satisfied that its working.
1) Bulk Administration > Phones > Export Phones > All Details
2) Bulk Administration > Upload/Download Files to download the exported
3) Modify the DN for 2 phones to test. Save the file.
4) Bulk Administration > Upload/Download Files to upload the changed
a) Select the Target = Phones
b) Select Transaction Type Insert Phones - All Details
5) Bulk Administration > Phones > Insert Phones
a) Select the radio button for Insert Phones All Details and select the
file name to be merged
b) Check the override the existing configuration checkbox
Are you getting this error “Installer User Interface Mode Not Supported. The installer cannot run in this UI mode. To specify the interface mode, use the -i command-line option, followed by the UI mode identifier. The value UI mode identifiers...
The below trick might come handy when you have to add a new node to a cluster but you don't have or is unsure of the security password for the publisher. This procedure has been around for ages.
1) Login into the CLI of the Publisher.