Sometimes you can get an image to ungroup in PowerPoint and then remove parts of it, like the arrows in your example.
It is best to work on a copy of your PowerPoint slide in case it doesn’t work and won’t let you undo.
Select Drawing from the View/Toolbars menu in PowerPoint. Then select Customize Views and Menus from the View menu. Click the Commands Tab. Select the Drawing category in the left sidebar. Scroll in the Commands window (if necessary) to the Ungroup command (mine was third from the top). Drag the Ungroup icon to the Drawing toolbar, it will show a solid black line where it is going to insert the icon. Select the picture and click on the Ungroup icon on the Drawing toolbar.
Sometimes it will warn that the object is a bitmap image and do you want to continue. You are working on a copy, so you don’t have anything to lose by selecting continue. Then it will either ungroup the parts of the picture or it will tell you it can’t do it.
That’s the best I know for what I think you want to do.