You didn't have this choice, but I only disassembly the bolt to replace a broken part, which is 99% of the time the extractor.
There's normally no reason to disassemble the bolt except to replace a broken part.
If you think it needs cleaning, spray it down with WD-40 and blow it out with an air hose. Then lube it.
A bolt disassembly tool is a must if you have to replace any parts.
BTW, if you shoot your Carbine a lot, pick up a spare extractor. It may save you a day of shooting.
I had another extractor break a couple months ago.