It's complicated whether or not you could do this. You definitely shouldn't try unless you are more interested in hacking hardware than in actually getting better performance.
Effective EGPUs require a high-speed connection to work. That limits their usefulness to thunderbolt (or similar custom connection) equipped laptops. While the PCI-E slots that support WiFi chips and hard drive in some laptops could be repurposed to support an EGPU, there are a lot of compatibility issues to work through, performance issues, and the hassle of needing to modify your laptop case to accommodate the extra cabling.
Since your laptop already has a decent GPU, it's really not worth it. If you need more gaming power, you could sell your laptop, build a...