What an interesting proposition. I should like to tell you not of something I've done alone, but something I did with my father after my mother died last year. A physicist by training and a retired engineer by profession, he decided that it was about time he built a petrol combustion engine from scratch. My mum died last October, and never one to dwell on sad things, my old man went out and almost immediately bought himself a 1960s 1000cc Ford Cosworth engine from Autotrader as an early Christmas present. It arrived in the guts of an old formula junior car, which we scrapped, having taken this (working) engine out. Over the next few months, each weekend we'd carefully pull the thing apart, clean all the pieces, and lay them out. We then put it back together, piece by piece, a process which took about another two months. In May, we tried to start the thing and it didn't work, so we started from scratch again, taking it apart, cleaning all the pieces, and (in July) putting it back together a second time (by this time, I'm afraid I'd lost interest in the project, but he valiantly continued). Again, second time around, the engine wouldn't start. In August, he took it apart for a third time, before putting it back together again, and at the beginning of October, he tried to get it going for a final time. No luck. So, a year on from mum's passing away, he went out, hired a JCB from the local Fork Rent, dug a massive hole in our back garden, and buried the engine.
I figure that's a pretty effective way of getting over someone.