There are a couple ways to do it. You could change the blog_posts_model::form_fields() method and unset or alter they type of fields to 'hidden' that are returned from that method.
Another, less obtrusive way may be to simply target those elements with CSS or Javascript. You can add to the blogs CSS file at fuel/modules/blog/assets/css/blog.css or you could add a javascript file that can be included with the page by adding it to the fuel/modules/blog/config/blog_fuel_modules.php configuration. Also less obtrusive would be to extend that blog_posts_model and overwrite that method and then change blog_fuel_modules.php to point to your model instead.
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Another, less obtrusive way may be to simply target those elements with CSS or Javascript. You can add to the blogs CSS file at fuel/modules/blog/assets/css/blog.css or you could add a javascript file that can be included with the page by adding it to the fuel/modules/blog/config/blog_fuel_modules.php configuration. Also less obtrusive would be to extend that blog_posts_model and overwrite that method and then change blog_fuel_modules.php to point to your model instead.
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