How to reduce video size to fit a webpage?


Hi guys

I recently bought a single license video to be used in my webpage( While evaluating we saw that the file size was 6MB which seemed good enough for the webpage. But after buying we noticed that it was actually a 421MB file ( Can someone please guide me how to reduce the file size here. The preview quality is good enough for us. We just want to remove the watermark. Please let me know how to fix this.