1)Copy "_loadouts.gsc" in "root/raw/maps" into "root/mods/mapname/maps"

2)Search there lines:

	set_player_viewmodel( "viewmodel_usa_marine_arms");
	set_player_interactive_hands( "viewmodel_usa_marine_player");

Change it to:

		set_player_viewmodel( "viewhands_black_kit");
		set_player_interactive_hands( "viewhands_black_kit");

3)Save ; go to mod builder ; check "loadout.gsc" and click on "build mod"

4)Enjoy!