PKHeX can import C-Gear skins from our event gallery using these steps:
Start PKHeX and load your save file.
Open your save file for Pokémon Black, White, Black 2, or White 2 using File -> Open...
Click "C-Gear Skin"
Click "Import .cbg/.psk"
Browse to the skin you want to use.
After opening the file, click "Save".
Save your save file