how to change DNS servers when using DHCP?

I have DHCP and there is NO WAY to change the DNS servers on my router (also, DHCP is either ON or OFF, there’s no way to configure anything about it like IP, range, etc). Terrible system, but there you go.

If I try to change the DNS server in the settings, I’m told “You may not change DNS servers when using the DHCP setting”. Oh.

What’s the way to do this? Just turn off DHCP and hope I don’t collide with IP’s on my lan?