It is indeed an Italian threaded bottom bracket (that's what the 36 mm x 24 tpi means). I can't tell if it's a sealed cartridge or a cup and cone but a proper lockring tool should be able to remove it.
You could replace it with a sealed cartridge bb as long as it's Italian threaded and has the correct spindle length and taper (JIS most probably based on the Shimano crank) or buy a matching bottom bracket and new crank as a pair.