Found this link which may help.
I haven't checked any further than what it says on the page, just so you know.
To install the app, download the .apk file to a computer and then transfer it to a remembered location in the tablet i.e. SD card (if installed) or internal storage
In the tablet go to Settings > Applications > Unknown Sources and enable it.
Then go back and open the My Files app and find the .apk file that you just transferred to the tablet.
Tap (double tap?) on the file to begin the installation of the app.
When it has been installed and you have tested that it works etc, go back and disable the Unknown Sources setting. This is so apps cannot be installed without your permission or knowledge.
Here’s a link to the user manual if you haven’t already got it.
Apologies if you know how to do all this already.