Open Clipchamp and start a new project
Import your video
Drag the video to the timeline
Click the video clip
Duplicate the clip if needed
Add a blur effect or blur filter to the duplicate
Place the blurred clip above the original clip on the timeline
Use crop or resize tools to isolate the area you want blurred
Position the blurred area over the part of the video you want to hide
Adjust the blur intensity if available
Trim the blurred section to match the needed duration
Preview the video
Export the finished video