Updating an infopath field of an active process

I am successful in updating datafiels of the active process without changing all of them with the help of k2rom connection method. I also want to change the xml fields of the active process instance data in my infopath process. I know how to change the k2 xml fields but can anyone give me an idea of how can I change an xml field of an active infopath process?

I am trying to built this as it is very helpful to fix errors without changing all the active proc instance data which it would if I try to change in error manager for the errored out processes.