Yep I do believe you are right about doing it on the PC. I don't see any utility function in the camera itself to unlock or change the attribute once set to read-only. I used Total Commander to go through the files and change those that were locked. I have a habit I need to break, of accidentally setting the lock protection on files by accident and had about 10-12 files I needed to un-protect.
For those who use any version of Apple's OSX operating system, here is a simple method of unlocking (or locking) any file.
● Select any locked file on your computer. In this case, it will be one of the G-Sensor locked dash cam video files in the folder you've copied to your computer from your microSD card.
● With the desired file selected and highlighted go to "File" in the menu bar along the top of your screen while in the Finder and then select "Get Info" from the associated drop-down menu.
● You can also access the "Get Info" window by selecting the file you want and then pressing one of the "Command" keys (the cloverleaf symbol to the left or right of your space bar) and then the "I" key (I=info)
●The "Get Info" window will open and you will see a check box with the word "locked". Simply uncheck the box and you have now unlocked your video file and are good to go.