How do I cahnge the ip address on the linksys spa941 when it failed to registered: it is not picking up ip address from the switch.it was working before change the switch

Confirmed modelLinksys IP Phone SPA941 and SPA962 with SPA932
Linksys IP PhoneThis document explains how to use Brekeke SIP Server with the Linksys IP Phone SPA hard phone .
The Standard features include two active line appearances, call forwarding, redialing, speed dialing, transferring calls, conference calling and accessing voice mail. For more information regarding this product please go to www.linksys.com
Configure Linksys PhoneSet up your Linksys phone with a fixed IP address (e.g. 192.168.0.15) and subnet mask (e.g. 255.255.255.0).

Once the IP address is configured you can access phone webpage by its IP from web browser (e.g. http://192.168.0.15). Network SetupClick on "Admin Login", then select “System" tab. Sign Static IP, Gateway and NetMask.

Use the following data as an example

• Static IP: Linksys phone IP (e.g. 192.168.0.17)
• Netmask: 255.255.255.0
• Gateway: not needed if SIP Server is in the same LAN as Linksys phone
• Click on [Submit all changes] button now to reboot you phone,
  or after whole setup is finished

• Proxy and Registration:
  
  • Proxy: Brekeke SIP Server’s IP address (e.g. 192.168.0.69)
    
  • Register: Yes
• Subscriber Information:
  
  • Display Name: extension number or Name (e.g. 400 or Alice)
  • User ID: extension number (e.g. 400)
  • If user authentication is set on at Brekeke SIP Server,
    type in the same information at Auth ID and Password as what you set at SIP Server side
    and Use Auth ID: Yes
• click [Submit All Changes] button to restart the phone