Edit Embedded Image Slides

I have a PowerPoint file that was originally downloaded from SlideShare, so every slide is a flattened image rather than editable objects. I only need three pages updated: • Slide 1 – replace several text lines and sharpen or colour-correct the background image so the new wording stands out cleanly... (Budget: ₹600 - ₹1500 INR, Jobs: Adobe Illustrator, Adobe Photoshop, Affinity Photo, Creative Design, Digital Art, Editing, Graphic Design, Image Processing, Photo Editing, Visual Design)