You'll need the unpackage.exe and unpackingGUI.exe from here:https://www.saintsrowmods.com/forum...saints-row-iv-and-gat-out-of-hell-tools.3188/
Its easy to unpack the files with the gui.exe then you'll need the 3dsmax importer also available in the tool section.I havent got the files anymore also i did just edit the .dds but not the meshes,so you have to do it by yourself.
Also youll need 3dsmax cause the importer is for the max and we have no other import tool for the mesh files as far as i know