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.