Nine out of ten times, that will result with an error reading "SAVE_STRING_MAX_SIZE exceeded in savegame" or something like that. I found this tutorial on an archived page of cfgmodding.com, but all the images are corrupt. Nonetheless, it still explains how to avoid the error and also why it happens. Maybe someone can develop a tool from reading this information.Seeing that the site that made it easy to do this thing is down. You will have to do it the old school way. That is using a hex editor to add in code into the save game.