Loading SIP Firmware on 7942g phones

[gmgarrian]

I have a number of 7942g phones currently with SCCP firmware.  These will be going to a client to use with non-Cisco call control equipment and I need to flash the phones with SIP.  I found a procedure to do this on 7940/7960 phones but the article was a bit dated and I'm not sure it still applies as the firmware file do not appear to match up:   http://www.cisco.com/en/US/products/hw/phones/ps379/products_tech_note09186a0080094584.shtml

So, my question is:  What would be the best way to get the SIP firmware on these phones?

[shrvaran]

The link you posted will not help converting 7942 phones.

You need SEP.cnf.xml, XMLDefault.cnf.xml and dialplan.xml files for converting 7942.

Please follow process used to convert 7965/7970's.

[gmgarrian]

It looks like I'll be able to use a retired CUCM server for this.  My plan is to update the server with the SIP firmware, set that phone model to use that firmware, and then have the phone boot and register to the CUCM which should kick off the new firmware download.