there should be an sd port in your computer/laptop. pop the card in, an auto play should pop up, or you can go to "my computer" and click removable disk. click import and import it to your photos or desktop, then go to facebook, go to videos, click upload, browse, then find the vid on your desktop or in your photos, select, open, and upload
If your sd card is in your phone and you have picture messaging email it to yourself, then download onto your computer and upload onto facebook. another way is if you have a port for an sd on your computer, just upload it onto your computer and then upload onto facebook.