• In Blender, I quickly made Geralt into a moustachy bad boi. Using it as an example, let’s import the texture to RedKit.

• Save a copy of your texture to any applicable format of your choice (Formats List)
  • I’m most comfortable using TGA (use RGBA, 32 bits, uncompressed)
  • Since I’m planning to replace original texture, I’m keeping the same name: h_01_mg__geralt_d01

• In your Asset Browser, locate a directory to import your texture to. Since I want to replace Geralt’s original texture, my destination is characters\models\geralt\head\model\
• RMB in your Asset Browser → Import → 2D texture
• In Import/Create resource popup, select a Texture Group that best suits your purpose. This determines what compression algorithm is applied to your texture. See Texture Group List for more info.
• WorldDiffuse would do for me. Hit OK.

• If prompted to Check Out, agree to it.

• If prompted to overwrite, agree to it.

• Seemed to work.

• Previewing textures on tiny balls may be a bit uneasy. So to see it better, I’ll locate an entity or mesh using the texture, and preview that instead:

Marvelous. We’re done here!

Other useful resources: