Any image editing program will allow resizing.
As you mentioned you have them 'saved in Photoshop elements' I assume you have not quite grasped what actually happens here.
The images are saved in a folder on the drive. Usually by default in 'My Pictures' or a folder the image editor has set up..
However simply open the editor- open the image you wish to reduce-
Go to the top tool bar and click on Image
[These are general instructions for most editors - 'elements should be the same] and click on re-size in the drop down menu- here you can selected the reduction method by percentage or to actual pixel dimension- click on save as and give the image a new name. this will preserve the original[just in case] and allow you to direct the new image to any location you have set up