Which command applies a skin?

SetWeaponSkin [Index] [ClassName], after typing EnableCheats in the console.

Normally 0. Weapons whose skin is split into two materials, such as the Bone Crusher or the Doomstick, use 0 and 1.

Where do I find class names for other skins?

In the skin packages under KillingFloor2\KFGame\BrewedPC\Packages\Weapons\Skins, or in the KFGame.KFWeaponSkinList source.

Cheats & Trainers (archive)

KF2 Hellmark Skin Pack: SetWeaponSkin Class Names

The Hellmark Weapon Skin Pack adds two themes, HellBlade and Thunder, for a dozen weapons. If you want to see them on a weapon before the pack is available to you, the guide shows how to apply a skin through the console. The author notes that at the time of writing you had to join the beta to see the pack at full release.

How to set a skin

Press F3 or the tilde key to open the console.
Type EnableCheats.
Type SetWeaponSkin [Index] [ClassName].

The index is usually 0. Some weapons keep their skin in two material classes (for example the Kriss has one for the body and one for the scope), so you set index 0 and 1 separately. The class name is the material that defines the skin. Example for a Kriss:

SetWeaponSkin 0 WEP_SkinSet47_MAT.Elite_Kriss.Elite_Kriss_1P_Mint_MIC
SetWeaponSkin 1 WEP_SkinSet47_MAT.Elite_Kriss.Elite_Kriss_Sight_1P_Mint

Cheats disable XP for the match, so use this in a private game.

Hellmark class names (set 48)

Each weapon has a hellblade and a thunder variant. Replace the first word to switch.

Weapon	Class name pattern
Dragons Breath	`WEP_SkinSet48_MAT.hellblade_dragonsbreath.hellblade_dragonsbreath_1P_Mint_MIC`
Fire Axe	`WEP_SkinSet48_MAT.hellblade_fireaxe.hellblade_fireaxe_1P_Mint_MIC`
Katana	`WEP_SkinSet48_MAT.hellblade_katana.hellblade_katana_1P_Mint_MIC`
Battle Axe	`WEP_SkinSet48_MAT.hellblade_krampusaxe.hellblade_krampusaxe_1P_Mint_MIC`
Hemoclobber	`WEP_SkinSet48_MAT.hellblade_medicbat.hellblade_medicbat_1P_Mint_MIC`
Pulverizer	`WEP_SkinSet48_MAT.hellblade_pulverizer.hellblade_pulverizer_1P_Mint_MIC`
RPG-7	`WEP_SkinSet48_MAT.hellblade_rpg7.hellblade_rpg7_1P_Mint_MIC`
.500 Magnum	`WEP_SkinSet48_MAT.hellblade_sw500.HellBlade_SW500_1P_Mint_MIC`

For the Thunder version, swap hellblade for thunder (for example WEP_SkinSet48_MAT.thunder_katana.thunder_katana_1P_Mint_MIC; the magnum is thunder_sw500.thunder_SW500_1P_Mint_MIC).

Two-part weapons

Bone Crusher (mace and shield):

SetWeaponSkin 0 WEP_SkinSet48_MAT.thunder_maceshield.thunder_mace_1P_Mint_MIC
SetWeaponSkin 1 WEP_SkinSet48_MAT.hellblade_maceshield.hellblade_shield_1P_Mint_MIC

(Use thunder_shield_1P_Mint_MIC for index 1 to get a full Thunder set.)

Doomstick (quad barrel), HellBlade:

SetWeaponSkin 0 WEP_SkinSet48_MAT.hellblade_quadbarrel.hellblade_quadbarrel_Main_1P_Mint_MIC
SetWeaponSkin 1 WEP_SkinSet48_MAT.hellblade_quadbarrel.hellblade_quadbarrel_barrel_1P_Mint_MIC

For Thunder, replace hellblade with thunder in both lines.

How to find other class names

Open the new skin package files with the SDK. They live in KillingFloor2\KFGame\BrewedPC\Packages\Weapons\Skins. Inside you will see folders (such as WEP_SkinSet48_MAT), groups (such as hellblade_dragonsbreath) and the material files (such as hellblade_dragonsbreath_1P_Mint_MIC).
Or read the game source KFGame.KFWeaponSkinList.

FAQ

Which command applies a skin?: SetWeaponSkin [Index] [ClassName], after typing EnableCheats in the console.
What is the index?: Normally 0. Weapons whose skin is split into two materials, such as the Bone Crusher or the Doomstick, use 0 and 1.
Where do I find class names for other skins?: In the skin packages under KillingFloor2\KFGame\BrewedPC\Packages\Weapons\Skins, or in the KFGame.KFWeaponSkinList source.