I just did this. The star pattern holding the blade in place was stripped because it became loose. I then broke a bolt on the housing trying to remove it. I was turning the right way, they just won't come out. Then the housing broke when I tried to mow. Might be easier to replace just the shaft but I didn't have that choice. Really tough to remove the top bolt if the blade is stripped though. Anyway, you need a cut saw, angle grinder, and sledgehammer. The sledgehammer is optional; it relieves stress to pound on the thing once in a while and curse the overpaid engineer who designed it. Remove the mower from the tractor. Remove the blade. Use the cut saw with metal cutting blade to saw thru the three arms. Reduce the size of the housing with the saw and the sledge until you can remove it thru the hole in the deck. Start grinding down the remaining three pieces still bolted to the deck, trying to grind to the bolt. At some point you will be able to remove the bolts, probably from the heat of all the grinding. Luckily the metal on the housing is relatively soft. I recommend a dust mask and eye protection so you don't breath metal dust or get it in you eyes. I can understand making this hard to remove but... If they just made the plastic shroud removeable it would be so much easier, you could just pop the bolt heads using a cheater bar. As it is you can barely get to the bolts to put the new one on, but it is doable. Make sure you tighten the bolts fully but be careful not to pop the head off. The bolts are self tapping. I destroyed the drive pulley getting it off (clamped in a vise) so I had to buy one of those too. Just mowed the yard and everything worked as normal. I'm keeping the blades tight because I do NOT want to Ever do this again. Sears wanted $99 just to come out and give an estimate. This made me mad enough to do it myself, and will probably cost them some of my business. Why do they need to come out at all? Just tell me how much it will cost; I told you exactly what I need you to do. Anyway, problem solved.
Frank, May 2010