Referring to your question, you can do as following to change some files' default player.
Select one of your files in finder and click right mouse> Get Info. In the Info window, go to Open with:
From the pull down menu select Macgo Blu-ray Player(or other player you would like to make default).
Then tick some file formats and choose the “make player my default player" button to assign that program to open that file extension by default.
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Right-click on the type of file you want to always open with VLC. Click 'Get Info'. In the 'Open With' section, select VLC from the drop-down menu. To apply this change to all files of this type, click the 'Change All' button.
For optical media, like CDs or DVDs, go to Apple -> System Preferences and choose "CDs/DVDs" in the Hardware section. Choose "Other Application" from the respective popup menu button. The list is alphabetical, so VLC should be near the bottom of the list.