ok, here is the way:
open pfm, open one of my mod, click on the xml file, make extract selected to your desktop. Your go to your destop, open the folder "shogun 2" then open the xml file with notepad. Your are now abble to modify the xml: change the numbers, copy and paste some units etc. When you have finished, you make "save". then you return to pfm, you click on your xml and make "replace file" with the xml that is on your desktop. Make save, that's it. And you can rename your mod.