Obtain Gapps from here, and then in fact you have two alternatives:

1. Install custom recovery via Odin and then flash Gapps with it.
2. Try to install Gapps via adb sideload. Not all devices/vendors allow this, but you can try.

Firstly you need enable ADB, then drop the Gapps zip-archive into folder with ADB and run

    adb sideload gapps.zip

There is also manual way of install (described for example here), but it's rather cumbersome.

Obtain Gapps from here, and then in fact you have two alternatives:

1. Install custom recovery via Odin and then flash Gapps with it.

2. Try to install Gapps via adb sideload. Not all devices/vendors allow this, but you can try.

   Firstly you need enable ADB, then drop the Gapps zip-archive into folder with ADB and run

   adb sideload gapps.zip
   

There is also manual way of install (described for example here), but it's rather cumbersome.