- BSA Browser
Start by downloading the BSA browser from the previously shared link. Download it by selecting the "Download (Manual)" button. A file titled "BSA Browser-59553-1-4-2.exe" should start downloading. After it's finished download, install the BSA browser through the installer (the .exe file), and follow the steps provided by the installer.
- Unpacking a BSA file
BSA files, or "Bethesda Software Archive" files, are essentially compressed archives that contain vast amount of resources. (IE, textures, meshes, etc.) To access the resources inside, we'll have to unpack them. For the item images, we'll need to unpack Skyrim's Skyrim - Textures.bsa and Skyrim - Meshes.bsa files. (I'm taking Skyrim as an example, it should work virtually the same for Morrowind and Oblivion.)
Start your BSA browser. Select "File -> Open Archive...", or press the shortcut "Ctrl+O". Navigate to Skyrim's Data directory. If you own the game on Steam, it should be "Steam -> steamapps -> common -> Skyrim -> Data". Double-click the Skyrim - Meshes.bsa file. This file includes virtually all of Skyrim's meshes, but we'll only be using the armor meshes for now. Select the small triangle in the lower left corner of the recently opened "Skyrim - meshes.bsa" file, and navigate to "armor". Double click that, and select "Extract all" in the lower right corner of the BSA browser tab.
Create a new folder titled "Skyrim meshes & textures" (Or something similar. It's your computer.) and navigate to it through the new screen that popped up after selecting "Extract all."
Select the folder, and select "Select Folder". The BSA Browser will now start unpacking the meshes.bsa file in this directory. Keep in mind that this will take a little while. After the meshes.bsa file has been unpacked, repeat this process for Skyrim's "Skyrim - Textures.bsa" file. It's important that you extract this file in the same folder as your meshes.bsa file.
- NifSkope 2.0
Download NifSkope 2.0 from the previously shared link. Under "Downloads" select the file titled "NifSkope_2_0_2016-11-07.7z", and wait for the .7z file to finish downloading. Create a folder titled "NifSkope 2.0" (Or something similar. Again, it's your computer). Open the .7z file with 7-Zip or WinRar, and extract all of its contents into the folder you just created. Your folder should now look somewhat similar to this: Open NifSkope by double-clicking the NifSkope.exe file.
The following steps are optional, but highly recommended. It will notably decrease the time it will take to remove the object from its background later on.
- Changing NifSkope's background colour
In NifSkope, select "Options -> Settings...". While in the Settings tab, select the Render tab, and the Colors tab. Under "Background", select a colour that will result in a large constrast between the item and its background. Preferably something bright, like purple (#FF00FF) or yellow (#FFFF00). Your NifSkope should now look like this: Go back to the settings tab, and select Resources. We'll need to link NifSkope to the folder in which you extracted your meshes and textures. In the "Paths" section, select "Add Folder" in the right section of the Paths section. Navigate to the folder in which you extracted your meshes & textures, and select "Select Folder". Your Resources tab should now have one folder in it, which is the folder you previously created to extract your meshes and textures in; Press G to disable the grid. Select File -> Open... in the upper left corner. Navigate to your meshes and textures folder. I've decided to get an image of the male variant of the Elven Gilded Armor, so I'll have to navigate to meshes -> armor -> elven -> m -> cuirass 0.nif. After you've found the armor you'd like to get an image of, double click it. NifSkope should now open a 3d render of the, in my case, Elven Gilded Armor; We'll now have to extract a screenshot of our "canvas". In the upper left corner, select "Render -> Screenshot". Underneath the "Image size" tab, select 2x. Give your screenshot an appropriate title, and extract it in your NifSkope directory. The screenshot should now be in your NifSkope 2.0 directory, in the folder "screenshots".
- Removing the item from its background
Start GIMP, or Adobe Photoshop. I use Adobe Photoshop, so I'm going to be using that as an example. Keep in mind that the process should work exactly the same for GIMP.
Open your screenshot in Photoshop, and crop your canvas around the armor piece; Select Select -> Color Range... in the upper left corner of your Photoshop screen. With your pipette, select the background, and click OK. Unlock the layer, and press Delete on your keyboard. Extract the image as a .png file. You now have a high resolution image of a Skyrim item;