After downloading the mod, use a program such as 7zip or WinRAR to extract the main folder of the mod.
Navigate to assets/mod_overrides. The assets folder is supposed to be in your game's installation folder (don't know where that is? click here). Create the folder if necessary
Move the main folder of the mod from step 1 to the folder you navigated to in step 2.
IF you have a HUD that changes the default logo:
go to \steamapps\common\PAYDAY 2\assets\mod_overrides > (HUD you are using) > units > menu > menu_scene > remove menu_cylinder_logo.texture
go to \steamapps\common\PAYDAY 2\assets\mod_overrides > (HUD you are using) > units > guis > textures > remove game_small_logo.texture and menu_title_screen.texture