I just did this on my 261 and it also did not have any tapped holes in my crank gear. The new Cloyes set I got from Patricks was tapped. When I removed mine I had actually removed my crank already because I was doing a complete rebuild. I just had the crank sitting on the bench and I pulled it off with 2-arm gear puller. It did not budge for quite a few turns and then all of sudden I heard a POP and it let go and it then came off quite easy with the puller. I am not sure if a 2-arm gear puller will fit better, but it may. I would still remove the front plate so you will have more room and you might as well replace the gasket behind the plate while your at it. I used an impact screw driver to remove those flat head screws, like the others suggested and it worked great. Good luck.
