Hey Zonk, if you want to edit your photos, do as listed below.
1- open folder on computer where pics are stored
2- right click on picture you want to edit and click edit
3- find button that says resize (if opened in paint, you should see it between crop and rotate)
4- resize by percentage, and drop down to 50%-25% total, make sure to click OK after
5- last, drop down the file menu and save as and rename it as you wish
That's all there is to it!
Best of luck
P.S.
If resizing it to 25% still isn't enough, then try shrinking more.