How to connect Nighthawk X4 R7500v2 and Nighthawk Mesh MK63

[andy_wu222]

Hello everyone, I have been using Nighthawk X4 R7500v2 for a couple years and kinda like it but then I dont get any good signal upstair, like 5-20mbps while downstair i can reach to 400+Mbps. I am having Spectrum internet with 400mbps plan. I recently bought Nighthawk Mesh MK63 (3 pieces) and didnt want to replace my old X4 because the XMK63 doesnt have many ports. Is there anyway to connect X4 and MK63 together for better  connection or should i get a different router to upgrade my old X4? 
I was trying to set both X4 and MK63 to the same network so then I can have acces to all my devices that already been set up with X4. 

I even follow step by step with this video https://www.youtube.com/watch?v=J5QJb3O19zI   but then i cant change the IP address from the MK63 because its 10x. space while the X4 is 192x. space.

Thank you so much and appreciate for your help

[plemans]

You can hardwire the R7500 to the MK63 system and set the R7500 in access point mode (or vise versa). 

I wouldn't unless you truly need another router as the MK63 is a pretty capable system and has 2 satellites plus router. 

And the R7500 isn't a mesh router and won't seamlessly integrate with the MK63. 

If you need more ethernet ports, I'd invest in an unmanaged gigabit ethernet switch. They're pretty cheap and work well.