Go to Design --> File Manager --> Move Files/Folders and find the image you wish to move to a new folder, click on the Move link next to the appropriate image.
On right hand side you can select the folder path to which the images will be moved.
Click on the "Click To Move Files/Folders" button, the image will then be moved. Repeat this process with each image you wish to move.
You can also upload images through FTP. To do that go to General-->FTP and follow the instructions.