you were right the first time.., I tried a few differant things and boolean is the fastest.
once you have you object cut , right click to 'edge select' pick all the edges where you want to bevel, you might try icking one edge and the 'select contiguous edges' (whatever its called,) when you find it, put it on your custom shelf, it comes in handy
anyway
from here
take it easy and life will be easy