I cored the exhaust on my Hypermotard 796
I didnt have to take off the exhaust or weld anything.
I used a rotozip to cut around the outlet pipe then used a dremil with a small cut off wheel to cut the outlet pipe from the inside out. That way when it falls off it will fall on the dremil and not down in the pipe.
Start cutting around the Edge of the outlet pipe
Use the Dremell with the cutting wheel to cut the pipe from the inside out
Remove the Pipe
Paint with Heat Black Paint
Here is a video of the finished exhaust. It has a much deeper sound and is not crazy loud. (Video still Processing so it should be up soon)
I didnt have to take off the exhaust or weld anything.
I used a rotozip to cut around the outlet pipe then used a dremil with a small cut off wheel to cut the outlet pipe from the inside out. That way when it falls off it will fall on the dremil and not down in the pipe.
Start cutting around the Edge of the outlet pipe

Use the Dremell with the cutting wheel to cut the pipe from the inside out

Remove the Pipe

Paint with Heat Black Paint

Here is a video of the finished exhaust. It has a much deeper sound and is not crazy loud. (Video still Processing so it should be up soon)