You will need to create what is known as an override for that snippet file. Override refers to your version of the default shipped files that will be used by Sublime Text in place of it’s default file.
To create an Override, you will need to know what file you have to override. In Sublime Text, you can do this by using
View Package File from the command palette.
So now create
Packages directory, place the snippet content there, edit the portion you want & save it. You should now get this snippet content every time you use it instead of the default one.