if I thought I moved into bike mechanic-ness* when I first broke a chain,
then I took a step further when I removed cranks for the first time.
just a tip:
make sure you really, really carefully thread the extractor deep into the crank before putting force into the extraction.
otherwise you can strip the first part of the thread out of the crank.
could turn a $300 crankset into something worth not very much
and cranksets hold their value better than almost anything,
except maybe a Technics 1200 turntable,
if they're looked after.
*definition of a real bike mechanic? someone who can lace a wheel I reckon.