You can do that with:
1) USB and PC (just connect it and the device will pop up like flash drive. You can manage your photos from there)
2) using your storage menu (some devices have auto transfer option)
read also this: http/www.tomsguide.com/faq/id-2908201/move-apps-card-android.html
At the bottom of the storage menu is "Transfer your data to SD card"