How do I remove hard-coded (or merged) subtitles or logo in a videos files?
You cannot remove them, the best you can do is to …
I find that any of the methods are not an improvement over learning a second language :-). When the picture moves behind them, the cloned blurred out mess there changes to try and "fix" it, whereas the subs themselves are more solid, and easier to ignore.
All of the above methods are also going to require a full decode and re-encode of the video, so it takes a fair amount of time The whole video is either going to look worse from the digital generation loss, or the file size is going to be bigger – because all high compressed video suffers from de-re-compressing, unless it is left more uncompressed.