If you want to remove Teacher icon from Course archive page and My courses page then you need to add the CSS code attached below to Edwiser RemUI settings > general settings > Custom CSS

1) To Hide Teacher icon from Course Archive page:
.pagelayout-coursecategory #categoryCourses .instructor-img {
display:none !important;
}

2) To Hide Teacher icon from My courses page:
.pagelayout-coursecategory #mycategoryCourses .instructor-img {
display:none !important;
}