how to remove background of photos

Put the photo on your Mac desktop. Open it in the Preview app. Do a View/Show Markup Toolbar. On the left side of the tool bar you will find the selection tools. Select Lasso from the drop down menu. Drag-select the photo's background. Press Delete on your key board to delete the background.

-- Rich

I used Photoshop Elements to remove/change the backgrounds of thee two images: