Fix it Tips

Start to put the pipe on the bike as if you were going to install it. Don't force the pipe into position. Line up the silencer end of the pipe where it should go and push the pipe gently until it starts to go into/onto the cylinder. Don't worry if the mounts are off, when you make the necessary adjustments and get the angle that the pipe enters the cylinder right, the mounts will fall into their proper position.
At this point you will see that it does not line up squarely with the cylinder and you will notice which way the header flange needs to be moved in order for it to enter the cylinder squarely. Take a mental note of which way it should be moved…left, right, up, down, etc.
Take the pipe off of the bike and put the lower pipe mount or tab (the one on the right side of the bike down by the water pump) in a vice or someplace to hold it still.
While holding the silencer end of the pipe with one hand (this will stabilize it so you don't just bend the mount), insert a 12"-18" lever (this can be a piece of pipe, a long socket extension, a broom handle, etc.) into the header portion or cylinder flange part of the pipe and with that leverage bend the pipe the needed amount (start with maybe ¼"-1/2") in the direction required.
Re-install the pipe. You might have to make a couple more small adjustments, following steps 1-5, in order to make it perfect. If everything goes right, your pipe should fit and mount up properly, all within about 10 minutes.