In simpler than it looks, but I couldn't find it. I leave it as a reference...
Open the *ODROID Utility* application.
Press the three point icon at the top right.
Press *Check online update*.
Wait for it to download and a message will appear. Click *Proceed* to restart and install the update.
Access from your Android browser to http://opengapps.org.
Select ARM for ODROID C1/C2, the version of Android you have (in my case, 6.0) and the micro or pico version. I always choose the one that occupies the least and install less components.
Once downloaded, we go back to *ODROID Utility*.
Press the three point icon at the top right.
Press *Package install from storage*.
Now choose the file that was previously downloaded from the browser.
Press *Proceed* and wait for it to restart, install and that's it.
Link: [codewalkerster.blogspot.com.es > How to install Google Play Store on ODROID](https://codewalkerster.blogspot.com.es/2016/06/how-to-install-google-play-store-on.html)
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