# nmcli con modify "eth0" ipv4.addresses "" ipv4.gateway ""

# nmcli con down eth0
Connection 'eth0' successfully deactivated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/5)

# nmcli con up eth0
Connection successfully activated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/6)

# ip a s eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 00:07:32:6f:6e:fe brd ff:ff:ff:ff:ff:ff
    altname enp3s0
    inet 192.168.50.203/24 brd 192.168.50.255 scope global dynamic noprefixroute eth0
       valid_lft 86397sec preferred_lft 86397sec
    inet6 fe80::207:32ff:fe6f:6efe/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

# sudo nmcli connection modify 'eth0' ipv4.method manual ipv4.addresses 192.168.50.151/24 gw4 192.168.50.254 ipv4.dns 168.95.1.1 +ipv4.dns 192.168.50.254

# nmcli con down eth0
Connection 'eth0' successfully deactivated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/6)

# nmcli con up eth0
Connection successfully activated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/7)

# ip a s eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 00:07:32:6f:6e:fe brd ff:ff:ff:ff:ff:ff
    altname enp3s0
    inet 192.168.50.151/24 brd 192.168.50.255 scope global noprefixroute eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::207:32ff:fe6f:6efe/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

$ sudo nmcli connection modify 'eth1' ipv4.method manual ipv4.addresses 192.168.1.172/24 gw4 192.168.1.1 ipv4.dns 8.8.8.8 +ipv4.dns 168.95.1.1