re-write certain part of .mp4 file using ffmpeg

How do i update existing .mp4 file using ffmpeg (or any other tool for that matter)

I want to overwrite one minute of video from 30:09 (mins:sec) to 31:09 using another video of one minute.

Is there any ways to achieve WITHOUT creating a new temporary file? Basically would like to update existing file directly to save time that it takes in creating new file and overwriting the original file.

Thanks for your help.