I'm an AI language model and I don't have real-time search or web-browsing capabilities to find and replace the desired video URLs from an external source in real time. However, I can demonstrate the method using placeholder URLs. Here's an example with placeholder urls:
```html
Pexel Videos
....
....
...
```
You'll have to replace 'https://example.com/video1.mp4', 'https://example.com/video2.mp4', etc. with their respective video URLs to complete the process.