You can't. The Wild Card: Change In Management quests triggers the Don't Tread On The Bear! quest. If you want to do all NCR mission but still fight for an independent New Vegas, you should finish the NCR quests befor the Benny/Yes Man quests.
there are tons of NCR quests to boost your NCR Fame to Idolized before you start yes man quests
But if you fail Don't Tread On The Bear! You'll be a Terrorist to all the NCR, instead of becoming a Wild Child.