I think if you need a stronger video card you'll need to sell the notebook you have and buy one with the hardware you require. Pretty sure Asus is soldering the GPU and CPU's to the mother boards now days.
If it is possible here is a link to some
980m for sale
G752VY-DH72 Win 10 Pro
512 GB M.2 Samsung 960 Pro
1 TB Samsung 850 pro 2.5 format
980m GTX 4 GB
32GB DDR 4 Standard RAM
Z97 PRO WiFi I7 4790K
Windows 10 Pro
Z97 -A
Windows 10 Pro