Hi Inderpreet, I hope you're doing well!
To flash a release device, you can use any of the KL26Z's supported debug interfaces and the MCUXpresso GUI Flash Tool. With this software, you will be able to directly program a binary file generated from an MCUXpresso project, or flash an arbitrary bin file generated in other software, like for example, a binary file generated with KDS.
You can read more about the MCUXpresso GUI Flash Tool in chapter 15 of the MCUXpresso User Guide, which can be found here.
You can also use interface specific software, like J-Link commander, to flash a binary file to a release device.
KL27Z MCU's support an ARM standard 2 Wire Serial Debug Interface that can be used for programming and debugging. You can read more about the SWD debug interface in chapter 9 of the KL26 Reference Manual, which can be found here.
Also, could you please take a look at the Kinetis Peripheral Module Quick Reference document, here? It also contains useful information about the available debug interfaces for Kinetis devices.
Please let me know if you need more information.
Best regards,
Sebastian