The IP address of your primary (1st) router will be the factory default - which in your case looks like its 198.162.2.1 .
Your second "router-to-be-AP" might alsp have that same default IP address, which is "no joy" - that won't work - but you need to have it as an IP address ON THAT SAME (192.168.2.xxx) network, just different IP address - that doesn't infringe upon the router's DHCP address space, either. (FYI: The latter is typically 192.168.2.100-200 or some such....)
So first off, if that's all you needed to know, then the answer is "use the FIXED IP ADDRESS of 192.168.2.2 ."
If that's all the you needed, stop reading and skip the rest!
Otherwise do it this way:
0) Assure that your existing router is working fine as-is, then TURN IT OFF.
1) Connect the NEW router-to-be-AP to your network and then connect to IT using the same IP address (for now) - 192.168.2.1 .
2) Once connected to it via your browser, navigate to it's main settings page and change its ("fixed" or "static") IP address to 192.168,2,2 .
3) Save settings, restart THAT (2nd) device, and see if you can now connect to it via 192.168.2.2.
If so, go into its settings and set it to be an "Access Point," save the settings, and restart your "is-now-an-AP" device.
4) Connect to it again (once restarted) at 192.168.2.2 and see that the settings took.
5) Restart you original (1st, now ONLY) router device.
All should work fine now. If not, power-cycle the AP and try again. (FYI: The ROUTER MUST always be powered up and be running before the AP device. Sometimes it works out when not done in order, but not always....)
GL!