It probably would've been helpful if you had a list of what to do:
- Launch the driver update executable
- After it unpacks and the actual update program launches, quit
- Open Device Manager
- Go to [PC-Name]->Display Adapters->[Video Card]
- Right click on it, select "Update driver software..."
- Select "Browse my computer for driver software"
- Point it to the path where the drivers were unpacked (it's usually C:\NVIDIA\[version])
Done and done. Optimus is working again after re-installing the iGPU. I guess the optimus settings got lost along the way last time. Thanks!