I think the danger posed by trolls in the mentioned areas is a bit overstated in the announcement.
Correct preparations require simply not washing yourself for some weeks (4 minimum),
not changing clothing, especially underwear and getting drunk every day for a period
of about 4 weeks as well to adapt the overall look and mouth odor.
UV lamps are a must in case you need to petrify the occasional troll
coming near the group, but swedish guides usually have some at hand.
Harsh colors like red or pink with green dots on your clothing should be avoided,
since it may provoke trolls attacks, even if you have managed to acquire the correct smell.
If an attack happens - "Duck and Cover" will most likely save you, since trolls usually do not attack
closely, but simply throw large rocks at their adversaries.
If you follow these simple guidelines (and the swedish locals have some more tricks I might not know)
the workshop should be as comfortable as a visit in Disneyland.
As you can see in the image below the locals manage to get really close to them,
protected by the mounted UV lamps on their specially equipped cars.
Using mobile lamps (preferably the type equipped with with fresnel lenses) strong enough to petrify a trolls leg usually does the trick when hiking.
Cheers
~Chris
