I want to run an XCOM rpg using the Dark Heresy 2e system. The players take on the role of XCOM operatives completing covert and overt missions against the alien menace. While converting the armory is simple enough, there are a ton of aspects of the Dark Heresy rulebook that are tied to the setting.
I can't convert the whole rulebook but I feel like I should do something with the character creation systems, and probably the talent systems as well. Just how much of the rulebook should be explicitly converted when switching settings this much?