I have killed all of the Brotherhood of Steel - what now? [duplicate]

in FO:NV, i killed all of the Brotherhood of Steel in the Hidden Valley Bunker. I then went to Deathclaw Promontory and picked up the power armour. I try to wear it and it says i have to have Power Armour Training. I've heard that i can only get the training from the Brotherhood, what are my options?

Thanks

The other remaining option for you to get the Power Armor Training is to do the For Auld Lang Syne quest given to you by Arcade Gannon. He's one of the possible followers and you can find him in the Old Mormon Fort.

To trigger the quest, you'll have to gain his trust or progress far enough or you can follow the quest line for the independent Vegas (Yes Man's quests) you can trigger it without gaining his trust.