Sur windows :

1. Open Notepad with administrator privileges.
2. Browse to C:\Windows\System32\drivers\etc\hosts (Or paste this into the address bar)
3. Open the file.
4. Make your changes and save

Sur Mac :

1. Launch Terminal
2. Type sudo nano /etc/hosts and press Return
3. Enter your admin password
4. Use the Return key to create some space below the existing records
5. Type in the TCP/IP address
6. Press the Tab key
7. Enter the domain name
8. Save the file by pressing Ctrl + O
9. Exit with Ctrl + X