How do I change Whatsapp tones to my own not from the Whatsapp predefined ones I want to change it to one that I downloaded off the internet but I dont know how to do that.
Put all your tones in InternalStorage/Notifications or InternalStorage/Ringtones. You'll now find them in ringtone list like esQmo said in the comment above (WhatsApp > Settings > Notifications). This works for all messenger apps.