Help a new modder

[IBreakPots]

So obviously I'm new to modding. I was trying to get my feet wet by watching a video tutorial on how to do some light modding to existing armor (http://www.youtube.com /watch?v=4Q8M4v1dYkc&feature=youtu.be&hd=1).

 

What's happening is this: I go to the object window, filter for IronCuirass and then proceed to Duplicate IronCuirass, IronCuirassAA, RecipeIronCuirass, and TemperIronCuirass because that's what I'm told to do. Then I go to my ArmorAddon for IronCuirassAA select biped model > edit > No files available. I did some digging and it looked like my .bsa files weren't extracted, so I downloaded BSAopt extracted them and then created a folder with the file path C:\Program Files (x86)\Steam\steamapps\common\skyrim\Data\Out and tried again. IronCuirassAA (the duplicate I created earlier) > Biped Model selected > edit > Previous file path to my desired .nif file > ERROR: Invalid Directory.

Incase I'm not being clear, the video does what I am attempting to do around 3:50. I can offer more information if it's needed. I just can't get it to do what I need it to do.

 

Again, being a newcomer to this type of thing, any help or advice would be appreciated.