Changing Co Version.dat?

back in the days we used to be able to modify or change the version.dat with hexeditor or reshack, but now it seems like its impossible. Is it encrypted now? or is it possible? Sorry if this thread exists im just newly back to elitepvpers and CO for that matter. Im not a leach this is a new screen name. Any help would be appreciated.

I'm opening the one for the current patch fine with a text editor. I don't know what you're doing wrong.

well i think im stupid. i change the dat file then start game and it just repatches. If i start game then try to change dat file it says its being used by another pro. I cut grass for a living i believe thats the problem.