Step 1. Use the list open files command to find the process using port 5434, for example.
sudo lsof -i tcp:5434
E.g. output:
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME com.docke 55746 work 18u IPv4 0x97cf67a7c0ce1ffb 0t0 TCP *:sgi-arrayd (LISTEN) com.docke 55746 work 19u IPv6 0x97cf67a7dd4c56d3 0t0 TCP localhost:sgi-arrayd (LISTEN)
Step 2. Kill the process by PID:
sudo kill -12 55746
Done!