It works!
Typing this message from it, inside MorphOS.
Only caveat is that the right USB port is no longer working. Probably I forgot to connect something.
Will post a picture soon!

I used the cheap hot air gun, measuring the temperature of the chip, trying not to go over 250f.
Circling around the borders of the ATI chip for 1m and 15s.
Reassembled and... It's working! :)

Let's see for how long.