As far as little bends on the exhaust pipe I didn't have any fancy tools when I needed to, I don't even have big bench vice so like bairedco I just used what I had around.
In my case that meant something heavy but not damaging to hold the pipe so I could bend it a bit and I found just the thing in my garage as well.
Hehehehe, ya, my Truck Vice ;-}
I just put a rounded kit mount bracket under the bend point to reduce any flat spot, a piece of 2x4 on top to bite in some to hold and not damage the tire, and then 'close the vice', hence lower the jack.
Then just a little slipper clad leverage and a slow pull.
All I needed was a little less angle so the pipe didn't hit the frame so I don't know if that will help the other way like your question going the other way, but it might give you some ideas how you could if think outside the box ;-}