The only thing I can see that the timing cover has to slide over is the output shaft: you've removed the clutch. The output shaft is the seven-eighths inch diameter shaft with a keyway, sticking a couple of inches out of the timing cover.
Your 60102 has a dipstick, where mine has a level plug (mine's ten years older than yours). You may need to remove the dipstick to remove the timing cover. I don't recall there being any dowel on the timing cover - if there were, you'd need to slide it very straight and square for the first quarter of an inch, to slide it off the dowel. I also may be missing something here - I've never dismantled that part of mine, and the overhaul manual treats it as trivially easy, just saying 'remove the crankcase cover' every time it comes up. What are the symptoms of it not coming off? Will it rotate around the output shaft?
