I have an issue that I need some help with as I'm not as tech savvy as I used to be.

I have my Verizon Model Fios-G1100 for my home network, in my den, by my computer.  I have Cat 5E lines that go upstairs for the kid's rooms on the other end of the house.  They also need to use WiFi from time to time for doing school work on the school supplied tablets, but the signal is weak. I have a Linksys EA7300 (AC1750) that I used to use & I have an extra Cat 5E line I can connect it to on my network.  

I have a TP-Link AC750 WiFi Extender set up, but it doesn't do the job & it cuts out every now & then. So I'd like to use the EA7300 as a WiFi extender instead.

Is this possible or is there a simpler, better, easier solution?

Thanks.

You can do that. It is a little bit of a process to do it right, but it isn't a huge deal.

Is there something else I could get instead, that would work just as well or better, & be easier for me to set up?
I'm not opposed to buying something instead.
@Imzadi

Yes....and no.

So the router that you have is three components in one box.
1. PAT Firewall. Takes one public IP address and allows multiple devices with private IP addresses to access the public network (Internet)
2. Switch. Takes one port on the internal computer that does #1 and gives you four available ports.
3. Access point. Connected to #2 and allows for wireless access.

To do what you want, you only really need #3. So you could buy an access point, but you don't really need to.

Broad strokes, here is what you do.

Start with your current network. We need to know what IP block you are using for your home network. Most of the time it will be 192.168.1.0 or sometimes a 10.
We need your current router's internal IP address. Your computer calls it your default gateway. Probably 192.168.1.1 but there are some weird people that use 192.168.1.254.
We will also need the subnet mask. This decides how big your network can be. Most are 255.255.255.0
Then you find an IP address for the new device. If your router uses 192.168.1.1 then try to ping 192.168.1.2 and see if it is available.

Then you configure your new device.
Give it the IP address you found (.2) the subnet mask and all of that.
Turn off the DHCP server
Turn off the WAN port
Set the wireless on the new device to match the old device. Same SSID, same crypto type, and same crypto key.

Then you take that wire that you have running to the new location and plug it into one of the LAN ports.

At that point your wireless devices can roam between the two access points seamlessly.
You can also plug fixed devices into the other LAN ports of the extension device.

2 watch outs to add:

Make sure the wireless networks are on different channels. Same SSID, Same security type (WPA2), same password, but different channels.

If your kids have iOS devices they lock into one channel and do not auto hop. So if they connect on one side of the house, and then walk to the other side, their device will not auto hop to the stronger signal, unless Apple has fixed that behavior. I had a mesh network setup at my last house and this behavior infuriated me. You had to disconnect and reconnect for it to connect to the stronger AP. I wound up buying a wireless AX router instead to overcome this.

Good add. Thank you.