just go to <Add CSS> & paste the code below:
.post-body img, .post-body .tr-caption-container, .Profile img, .Image img,
.BlogList .item-thumbnail img {
padding: 0 !important;
border: none !important;
background: none !important;
-moz-box-shadow: 0px 0px 0px transparent !important;
-webkit-box-shadow: 0px 0px 0px transparent !important;
box-shadow: 0px 0px 0px transparent !important;
}
