Well, I could give you a thread that shows how to butcher a roo, but I don't think it's what you want in this case.
I'd just start detaching myself from the roo; spend less time with him, distract yourself with other things and mabe in about two weeks think about it again.
On the other hand, you could get someone else to slaughter him. Check for people in your area, or get a relative that can do it. Dont think about the roo.
Or mabe just do it. Get over the relationship, and get it over with quickly.
Mabe you could try an online site such as craiglist, or advertize in the local paper, or give him to an animal society
I have no idea what I'd do in your situation...
I wish you the best of luck;
Daisy
(edited to add) check out the meat birds section; I'd imagine they'd have some more ideas on how to do this...