I made some changes to my /etc/inittab file. How can I make those changes effective without rebooting?

To make changes to the /etc/inittab effective without a reboot, issue either of these two commands as the root user:
# init q

# telinit q
The init q or telinit q command wakes up init and tells it to re-examine the /etc/inittab file so changes to the file are effective immediately.