Can you find Hancom Office in the Galaxy Apps Store? If so, then you should be able to install it. Multiple office suites on the same device shouldn't interfere with each other (unless the one on your phone is another version of Hancom Office--that might cause some confusion).
How does it want to override? Do you mean that Polaris has been set as a default? You could try going to the App Manager, select Polaris, and Clear Defaults.
I will have to wait a couple days tilly wife comes home so I can work with her phone.
But when I being Hanson office up.
It shows Polaris is actually running.
Don't want mess up the OL phone.
She tends to scream.