Go for it dude. It's a 13mm socket. I just put my new upgraded brakes on my car, dropped her back down, and then decided to realign my GT500s after I took the floor jacks in. My car is low. 1.7in drop. I did it in under 5mins each side. No jacks needed.
Here is the result. Snug and centered.

 

Super easy to align, and to get the tip in you will need to loosen up the clamp at the over the axle pipe and mid pipe and slide it in there.
BTW I have seen a lot of Mustangs come out with one tip sticking out more than the other from the Factory.

 

For the tip sticking out too much, you may have to take the clamp loose between the mid pipe and over axle pipe to make the correct adjustment.

 

Thanks guys. I think I'm going to leave it for now. I am confident I could adjust the axle-back clamp but when we're talking about the H pipe I start to lose confidence that I could DIY. I was thinking of doing the Boss quads and if so I'll have the installer fix them.