If you want to use (the official version of) Coldfire Lite, you'll have to step back to Codewarrior 7.1 as CF Lite is not compatible with CW7.2. Of course, compatibility issues can be fixed, which I did. You can find the fixed version here:
http://www.mvdh.be//CF_Lite_32_patched/7.2 REG_ABI 20101024.zip
It contains targets for MCF5223x and MCF52259 cpus and all sample code has been stripped of.
How to merge your code to CF Lite I cannot tell. Depends a lot on how your code has been built up I guess. It may be a better idea to take a look at FNET, which is made to add network connectivity to existing applications. See:
https://community.freescale.com/thread/57196