1- Drag & drop these folders in your WaW Root.
2- Open Radiant & Right click --> Misc --> Prefab and go to _prefabs ==> tim ==> weapons and add the k7.map.
3- make sure it's halfway through the wall (The chalk is the one you need to focus on).
4- go to your mod ==> maps and open _zombiemode_weapons.gsc.
5- add this lines here where it says (// Full Auto) : 

	add_zombie_weapon( "k7_zm", 			"Hold F For K7 [Cost : 1250]", 				1250,	"vox_ppsh",				0 );
	add_zombie_weapon( "k7_zm_upgraded", 			"", 				1250,	"",				0 );

BTW : I have already made the hintstring, just if you want. Change the price.

6- By all means, wall weapons shouldn't being added to the box, but if you insist. Open dlc3_code.gsc and go the same (// Full Auto) and add these 2 lines :

	include_weapon( "k7_zm" );
	include_weapon( "k7_zm_upgraded", false );

7- go the raw/images and search for k7_chalk.iwi. copy it to your mod/images. Compile & Build.