For Newer version of Edwiser RemUI theme (It will work for version Edwiser RemUI 3.7.5 and above)

Add this CSS in Edwiser RemUI general settings >> Custom CSS section:

While using Edwiser Course format in the course:
#page-course-view-remuiformat #nav-drawer-container a[data-key="grades"] {
display:none;
}
#page-course-view-remuiformat #nav-drawer-container a[data-key="participants"] {
display:none;
}

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While using other Course format in the course:
#page-course-view-topics #nav-drawer-container a[data-key="grades"] {
display:none;
}
#page-course-view-topics #nav-drawer-container a[data-key="participants"] {
display:none;
}


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For Older version of Edwiser RemUI theme (It will work for versions till Edwiser RemUI 3.5.11, Edwiser RemUI 3.6.7 and Edwiser RemUI 3.7.4)

Add this CSS in Edwiser RemUI general settings >> Custom CSS section:

While using Edwiser Course format in the course:
#page-course-view-remuiformat .site-menu-item a[data-key="grades"] {
display:none;
}
#page-course-view-remuiformat .site-menu-item a[data-key="participants"] {
display:none;
}

___________________________________________________________________

While using other Course format in the course:
#page-course-view-topics .site-menu-item a[data-key="grades"] {
display:none;
}
#page-course-view-topics .site-menu-item a[data-key="participants"] {
display:none;
}