First Login into your Godaddy account. Click the 3 dot button and select manage DNS
Now Scroll down and go to Nameservers.
Click the Change button.
Next choose I will use my own name servers.
Now click enter my own name servers.
Enter these 2 namecheap servers which you received mail from namecheap for hosting purchase.
Click Save button.
The name servers will be updated within 24 to 48 hours for us it took less than 5 minutes.
You will also get a confirmation mail on name server update from Godaddy.