Copy install.wim and boot.wim from the sources directory in the iso to a temporary place accessible from a Windows machine, as you will need to use DISM, a built-in command-line tool in Windows.

From inside Windows, create a directory called mount in the same location as the .wim files. Create a folder called USB3 in the same location. Inside the folder called USB3, create another called x64, where you will place the x64 USB 3.0 drivers that you will load. If you’re installing USB 3.0 drivers for an Intel NUC, those drivers can be found here.

Then, run the following set of commands to load those drivers into the .wim files. For the first command, you can determine the correct index by using the method from the previous post. For the second two times, you must use index 1 and then index 2.

dism /mount-wim /wimfile:install.wim /index:3 /mountdir:mount

dism /image:mount /add-driver /driver:USB3\x64 /forceunsigned /recurse

dism /unmount-wim /mountdir:mount /commit

dism /mount-wim /wimfile:boot.wim /index:1 /mountdir:mount

dism /image:mount /add-driver /driver:USB3\x64 /forceunsigned /recurse

dism /unmount-wim /mountdir:mount /commit

dism /mount-wim /wimfile:boot.wim /index:2 /mountdir:mount

dism /image:mount /add-driver /driver:USB3\x64 /forceunsigned /recurse

dism /unmount-wim /mountdir:mount /commit

Then, copy install.wim and boot.wim back to the temporary directory where you placed the files from the iso, replacing the old versions of install.wim and boot.wim.

Create the patched ISO. This must be done from Linux again, from inside the previously mentioned directory:

mkisofs -o ../win7.iso -b boot/etfsboot.com -no-emul-boot -boot-load-size 8 -iso-level 2 -udf -joliet -D -N -relaxed-filenames .

Most credit goes to Intel and Chris Hoffman.