Paint offers the option to remove the background of a picture, to see the necessary steps select your version of Office:
Windows (versions 2019 or higher)
Instructions for newer versions of Paint
1. Select the picture that you want to remove the background from.
2. On the toolbar, select Picture Format > Remove Background, or Format > Remove Background.
If you don't see Remove Background, make sure you have selected a picture. You might have to double-click the picture to select it and open the Picture Format tab.
3. The default background area will be colored magenta to mark it for removal, while the foreground will retain its natural coloring.
4. If the default area isn't correct, go to Background Removal > Picture Tools and do one or both of the following:
- If parts of the picture that you want to keep are magenta (marked for removal), select Mark Areas to Keep and use the free-form drawing pencil. Pencil used to draw tables to mark the areas on the picture that you want to keep.
- To remove more parts of the picture, select Mark Areas to Remove and use the drawing pencil. Pencil used to draw tables to mark those areas.
5. When you're done, select Keep Changes or Discard All Changes.
To save the image in a separate file for later use, right-click the image and select Save as Picture.
You can apply an artistic effect or add picture effects to the picture remaining after you've removed the background.
Instructions for Office 2016-2010
1. Select the picture that you want to remove the background from.
2. Under Picture Tools, on the Format tab, in the Adjust group, select Remove Background.
3. Click one of the handles on the marquee lines and then drag the line so that it contains the portion of the picture that you wish to keep, and excludes most of the areas you wish to remove.
You can sometimes get the result you want without any additional work by experimenting with the position and size of the marquee lines.
Tip: To undo marked areas, select Delete Mark and then select the line.
4. If the default area isn't correct, go to Background Removal > Picture Tools and do one or both of the following:
- Select Mark Areas to Keep and use the drawing pencil
to mark the areas on the picture that you want to keep. - Select Mark Areas to Remove and use the drawing pencil
to mark those areas to remove.
5. When you're done, select Keep Changes or Discard All Changes.
To save the image in a separate file for later use, right-click the image and select Save as Picture.
Instructions for macOS
1. Select the picture.
2. On the Picture Format tab of the ribbon, select Remove Background.
If you don't see Remove Background or the Picture Format tab, make sure that you've selected a picture. You might have to double-click the picture to select it and open the Picture Format tab.
3. The default background area is colored magenta to mark it for removal, while the foreground retains its natural coloring.
4. If the default area isn't correct, under Picture Tools, on the Background Removal tab, do one or both of the following:
Select Mark Areas to Keep and use the free-form drawing pencil
to mark the areas on the picture that you want to keep.Select Mark Areas to Remove and use the drawing pencil
to mark those areas to remove. 
5. When you're done, select Keep Changes or Discard All Changes.
To save the image in a separate file for later use, right-click the image and select Save as Picture.