Hi Sunita, although you are asking for customization and it’s beyond the scope of support. But I am providing you the custom codes. Hope it will work.
• First to hide the modal text add this css.

.rex-modal .rex-content figcaption {
display: none;

• Then remove margin and padding of the image and add your desired width.

section.rex-works-showcase .rex-modal .rex-content img{
width: "Your desired width";
margin: 0;
padding: 0 !important;