How to Remove Blade from Lawn Mower

My blade is on a spline and wont come off after I remove the center bolt. Tried crc on it and tried hitting with a mallet. Still no luck.

how do you take off that part connecting to the crankshaft? I'm trying to get the lower portion of the engine casing off the crankshaft but that part is stopping me.

Missing first step on video: Remove spark plug wire from spark plug.