Odin is a small tool designed to help Samsung users that are looking to update their smartphones and tablets manually to a brand new official Android firmware. The Odin3 v3.10.7 program has been released to be used for the Android 6.x Marshmallow and older firmware versions.
This app should be used only by advanced users. Don't try to use the Odin 3 v3.10.7 program to upgrade your Samsung phone or tablet in case you are a beginner and you've never flashed anything until now.
For Odin to work you will need to install it on your computer and make sure that the latest Samsung USB Drivers are installed, too. Also, you need to make sure that your PC doesn't have the Samsung KIES running, as KIES will attempt to block Odin from opening.
Download the Samsung usb drivers from here. Install the drivers on your computer, make sure that KIES is disabled and that no antivirus blocks Odin from launching.
In order to make sure that your Samsung device is detected by the computer and that you will be able to complete the updating process successfully, then you need to enable USB Debugging from its Developer Options menu.
If you cannot find the Developer Options menu, then you need to go to Settings> About Device and tap 7 times consecutively on the Build Number section. Return to Settings, scroll down and there you should find Developer Options menu> open it and find USB Debugging option. The USB Debugging allows your Samsung device to detect the PC and connect with Odin program successfully.
In Odin you should disable the 'Re-Partition' option always before starting an updating process. Do not edit any other different Odin options and don't change anything under the "pit" section.
In order to complete an update using Odin you simply need the Android tar.md5 firmware file to be added in "AP" and for you to hit the START button. If you're planning on flashing the whole operating system, then you will need the bootloader image to be added in BL, for the system tar.md5 in AP, the modem image in CP and the cache and other hidden CSC features to be added in CSC. The files that you will need to flash will always feature the BL/ AP/ CP/ CSC value in their file name.
Prior to starting the Android update you need to put your Samsung device in Download Mode. This is done for almost all Samsung smartphone and tablets by pressing and holding Volume Down, Home and Power buttons at the same time. Release the buttons when the warning screen loads and then press Volume Up to confirm Download Mode boot.
Note that every time you use Odin3 to update the Android firmware of your Samsung phone, the first boot process of the newly flashed ROM will take at least 10 minutes before it completes.
Download ODIN3 v3.10.7 from here.