Oh ok to do so just add this to the list here below at template.css at line 1308:
.social_icon, .s5_pricetable_column .price, #s5_is_leftarrow, #s5_is_rightarrow, .s5_testimonials, .jdGallery a.right, .jdGallery a.left, .s5_tab_show_slide_button_active, .s5_agenda li.left .dot, .s5_agenda li.right .dot, a.s5_scrolltotop, .button, .readon, p.readmore a, a.k2ReadMore, .userItemReadMore, div.catItemCommentsLink, .userItemCommentsLink, a.readmore-link, a.comments-link, div.itemCommentsForm form input#submitCommentButton, #s5_register, p.readmore a, a.readon, #myGallery a.readon, #s5_login:hover, .rslides_nav.prev:hover, .rslides_nav.next:hover, #cboxLoadedContent .button, #s5box_register_inner .button, button.button, p.readmore a.btn, a.button, #s5_component_wrap .pagenav a, .ion-ios-play.sized, .s5_is_slide_css a.btn, .s5_agenda .overlay_hover_outer, .s5_agenda .overlay_hover_inner, .button, .readon, p.readmore a, .btn, #cboxLoadedContent button {
border-radius: 100px !important;
}