在现有项目中向新设备添加配置文件

I'm confused as to how to add a provisioning profile to a new device. So I'm using Xcode 4.3.2, and TestFlight. I was given a pre-existing project and a team license via the company I'm helping out. The provisioning profile on developer.apple.com had certain devices already set up. So I added all these devices as testers to TestFlight, sent out an archived build, no problems, worked fine.I'm confused as to how to add a provisioning pr