Perhaps it took 3 hours because it was a bit tricky?
You did say yourself that it looked a bit tricky.
I'd wager a bet that you've answered your own question.

You don't need three hours.  You do need to remove the passenger side
wheel arch, loosen the belt to remove the crank pulley.  An impact
wrench helps but not absolutely necessary.

The most elegant way of removing and installing the belt is to use a
1/2" drive 18" long breaker bar with a 19 mm short socket.  Stand in
front of the car facing the rear with the hood open.  Slip the socket
onto the nut on the tensioner and start pushing the breaker bar toward
the rear.  The tensioner will gradually give way.  When it does the
belt will be loosened.  Keep the force on the breaker bar with your
right hand.  Crouch down to remove the belt with your left hand.
Remember the belt routing.  Installation is the same way.  You do not
need any special tools to remove and install the serpentine belt.

The crank pulley needs a 27 mm socket.  If you do not have a helper,
do the following.  Shift the gear into fifth.  Slip the 27 mm socket
and the breaker bar on and have the tip of the bar rest on the
ground.  Then put the tire and wheel lug on hand tight.  Rotate the
tire to loosen the crank pulley nut.

It is critical you tighten the crank pulley nut to 129 ft-lbs.  A
loose crank pulley could spell disaster.  The engine timing depends on
it.  A loose pulley could mean the timing chain slipping relative to
the cam shafts.

One should be able to do it in less than an hour.  Experience has
taught me to replace both pulleys at the same time.  Just remember
that the tensioner pulley's nut has a left handed thread.  Two people
can do it with a breaker bar alone but a suspension spring compressor
works well to compress the tensioner.   There is no need to remove the
wheel well liner.   One can feed the belt around the proper pulleys
with the aid of a trouble light, a yard stick and maybe the hook of a
clothes hanger.