Convert Files' Name To Utf-8?

You can try "man iconv" in the terminal. iconv is the tool that can convert between text encoding formats.
I found a couple of sites that offer some command line stuff to convert from Windows-1252 to UTF-8 - Such as
I DO NOT know if this will work for you, particularly if you have a recent OS X version (Yosemite or newer.) I haven't tried that type of conversion. But the command is there and available for your use. You may need to adapt to your own use.
The last line is probably the most important for you to remember
backup the whole directory tree before executing any such command!