1. Port JBPatch to the K4.
2. Decompile the firmware to find where the respective functionality is implemented.
3. Write patch to adapt the functionality. (Check the first post for links to two small HOWTOs)
4. Publish the results of 1.) and 3.) here.
If you are having problems with a particular step, feel free to ask - but please, precise and specific questions.
And, read this first:
http://whathaveyoutried.com/