How do I turn off my iPhone text messages showing up on my imac home computer?

1. On your iPhone, go to Settings > Messages > Text Message Forwarding.
2. 
3. Choose which devices can send and receive text messages from your iPhone. Disable where you do no not want the messages.
4. 

Following those (and all Apple steps) has not worked for me since I bought a new MacBook with Big Suck preinstalled.

Remember the good old days when all you had to do was be logged on to iCloud with the same ID on the other devices.

Well Apple upgrade SOL strikes again.

Why do I not see “Text Message Forwarding” when I go to Messages settings?