Changing Gear in SimC

[Pruka]

Still fairly new to using simc and wanted to ask how I could change gear? I have the level 2 engineer helm and as well as a 676 helm. I want to sim the difference between the level 3 helm and the 676 helm to see if it is worth upgrading the engineer helm. I have read the online wiki and I still do not see where it tells me how to change to gear I do not have. It would also be nice to be able to change out other items for example my 645 bracers with MS to see if the heroic bracers are an upgrade before I take them from a fellow player.

If anyone could help me out I would appreciate it.

[Deleted]

One of 3 options:
Askmrrobot: it's somewhat easy to navigate, you filter stuff and you click stuff until you have the gear you want to sim, and you press the Export to SimC button. Copy/Paste into the Simulate tab and run.
Find the item yourself: http://www.wowhead.com/item=113851/reavers-nose-ring&bonus=0 bolded after the "item=" is the itemID, similarly it looks like id=113851 in Simulationcraft.
Simulationcraft addon: /simc, copy/paste, run. switch item, /simc, copy/paste, run. Easiest method of simming different items by far but you can only do it with items you actually own.

[Pruka]

Thank you for the help