1 Visit the http://support.polycom.com/PolycomService/support/us/support/voice/page and select your phone from the list.
2 Locate BootROM 4.5.0 B Downgrader under the Downloads section and save the files onto your
3 Unzip BootROM 4.5.0 B Downgrader.
4 Copy the <partNumber>.sip.ld files from the Downgrader onto your provisioning server.
These <partNumber>.sip.ld files contain both Downgrader and UC Software 3.3.2 images.
5 Reboot your phone.
Your phone will downgrade and do the following:
○ Reformat the file system
○ Install a new UCS 3.3.2 image — contained in the <partNumber>.sip.ld image
Your phone is now downgraded to BootROM 4.5.0 and UC Software 3.3.2.