I noticed after installing this and reading from others that some have had issues with the main support tab fitment under the rearsets and some have not who explained the issue but not clearly. FYI, this header is from the very first shipment that Anthony brought over for the Hyper (just really late installing it).
Here it is, the header system is designed to fit the stock mounting holes available as designed for the Multistrada.
On the Hypermotard, there is an aluminum spacer that is installed between the right bottom rearset allen bolt and the cat. This spacer is #32 in the image below. You need to loosen the allen on the rearset (I just loosened the rear brake pedal and pulled it out to give me access) and either find suitable spacers after you pull out the stock spacer OR, what I did, simply rotate this spacer down while still on the allen to expose the threaded hole it was covering that is where you will mount the Zard headers. The cylindrical index that fits into the hole you will mount to was very shallow on mine and I was able to just pull it out slightly and rotate.
That's it, no drilling or slotting required.
Here it is, the header system is designed to fit the stock mounting holes available as designed for the Multistrada.
On the Hypermotard, there is an aluminum spacer that is installed between the right bottom rearset allen bolt and the cat. This spacer is #32 in the image below. You need to loosen the allen on the rearset (I just loosened the rear brake pedal and pulled it out to give me access) and either find suitable spacers after you pull out the stock spacer OR, what I did, simply rotate this spacer down while still on the allen to expose the threaded hole it was covering that is where you will mount the Zard headers. The cylindrical index that fits into the hole you will mount to was very shallow on mine and I was able to just pull it out slightly and rotate.

That's it, no drilling or slotting required.