Post by Coralanth
It really is quite easy and it makes questions about gemming and enchanting a lot simpler to answer as well.
On the import tab, find your character in the armory. Once you get to your character page, click the import button.
After a second it will show the simulate tab with your imported character.
You'll see a bunch of text along the line of this:
#!./simc
warlock=Coralanth
origin="
http://us.wowarmory.com/character-sheet.xml?r=Aggramar&n=Coralanth"level=80
race=blood_elf
....
head=hood_of_smoldering_aftermath,stats=269armor_74hit_82haste_131sp_103sta_103int,gems=chaotic_skyflare_12sp_10spi_9sp,enchant=30sp_20crit
neck=evokers_charm,stats=42haste_74sp_63sta_43int_41spi
shoulders=pauldrons_of_catastrophic_emanation,stats=248armor_67hit_59crit_109sp_77sta_77int,gems=23sp,enchant=24sp_15crit
chest=merlins_robe,stats=331armor_66crit_90haste_131sp_103sta_103int,gems=12sp_10spi_10haste_12sp_23sp_9sp,enchant=10str_10agi_10sta_10int_10spi
...
Click simulate to sim where you are now. The results will show up in the aptly named results tab.
GO back to the simulate tab and click the left arrow in the bottom left. Those are like history buttons.
Make some changes in your gear on this tab and simulate again.
Rinse. Repeat.