[Nachoman]

So, did he use a ladder, or did he clamber up the air conditioners to the roof?

[slag]

I do not believe he climbed up on the air unit, it is too far away from the building as you can see in the video below at the 0:12 mark;

https://www.youtube.com/watch?v=-F87LPOdGiA

And here is an arial view that shows just how far the unit (center top) is from the building;

https://www.facebook.com/skynews/videos/aerial-pictures-appear-to-show-a-rifle-next-to-what-appears-to-be-a-body/845314960358484/