Download the latest version of WhatsApp from Google PlayStore.
If you have the app, just update it to the latest version.
Open WhatsApp.
Tap on the contact's name you wish to share the video with
Tap on the attachment or the paper clip icon.
Record a new video or select Gallery and then the video.
The video will appear on your screen, and you can alter it from here.
You will see a small speaker icon right beneath the video frames. Tap on it to mute the video.
You can press on Send once this is done.
If you don't see the video icon even after the update, you may have not received it. So just wait for a while.