regarding unscrewing the kit lens, I do this quite often as I dont have a manual wide angle lens. You just hold in the release button and gently turn the lens until you hear the contacts disengage. You have to sort out all your settings first.
Dragonframe is fine with it but im not sure about other software.
Also I dont know if this damages your camera but mine has been fine for the last year.
Here's a demonstration on how to do the lens twist method on a Canon: https://vimeo.com/30974031
I have lots of other good info listed on my blog (a good idea to bookmark this link so you can always find it):
I bought the 600D. First I got it with a STM lens. But the focus (also manual) on the STM only works when the camera is on. So after you unscrewed the lens you can’t focus. So I changed it to the IS II.
Thanks everyone for your input and help
On Canon STM lenses manual focus is electronic.
It only works if the camera is on and awake.
The focus ring is only input to a computer, which then moves the lens (focus). So the lens need to been connected to the contacts and therefore the lens can’t be unscrewed if you want to be able to focus.
Oh, it's a Canon lens. Now I understand. If it has to be controlled electronically, it isn't really what I call a manual lens.