He must check out the file to the working directory on his machine and take ownership of files he wants to modify. This way he would have all the required files (hopefully the toolbox or library files don't create issue). And then when he is back he can check the files into the vault.
You can try the scenario before he moves out.
In case he wants to use pack and go, then make sure "Flatten to single Folder" is not checked. This way all directory structure will be preserved but I'm still not sure as how Pack and Go would be helpful.