1. First open the PR software.

2. Then find the project bar at the bottom of the interface.

3. Right-click in the blank space and click Import in the interface that appears.

4. Select the video and drag it to video 1 on the right.

5. Select the razor tool on the left side of the interface.

6. Crop the video at 10 seconds, and then crop it again at 12 seconds, that is, the video is divided into 3 parts.

7. Click the selection tool.

8. Select the middle 10 seconds to 12 seconds of the video, right-click and select Speed/Duration.

9. Modify the speed and the duration will change accordingly. Check the ripple edit and click OK.