This reminds me how I recently upgraded MorphOS from 2.3 to 2.5: Entirely by hand! I have a small system partition (on purpose) and the new installer refuses to install fresh or update because it wants 170 MB (booooooo!).

So I just opened two listers, left and right of the screen. On the left, the 2.5 CD contents. On the right, the 2.3 running system. I carefully replaced everything in the later (except ENVARC) which was updated in the new version. My system has some components that I don't use removed, and I didn't add newer versions of them.

Afterwards, I ran the scripts to set correct file attributes in "S" and "C", and voil?, I'm on 2.5, with the preferences set from 2.3. All this can be done perfectly on the thirty minutes that the demo version allows.

I don't belive this leads to a perfect system, but indeed it starts and works stable, at least for a quick test. Being able to replace files on a live, working MorphOS system, is lovely!