The physical button of the Samsung Galaxy S8 and the Galaxy S8 Plus that activates Bixby by default can be remapped to instead launch the Google Assistant, users have revealed. A free Android app called All in one Gestures is able to accomplish that task in just a few simple taps, as one user was able to remap the physical button on a display unit of the Galaxy S8, as evidenced by the video below. The app in question is already available for download from the Google Play Store and you can access its listing by following the link beneath this writing.
Once you've installed and launched All in one Gestures on your Galaxy S8 or Galaxy S8 Plus, you'll be prompted to allow the app to access your system settings. Once you've done that, you'll be presented with the app's main interface from where you have to swipe left to navigate to the Hard Keys tab. You want to enable this functionality, which will open another window on the bottom of the menu where you'll be asked to turn on the app's Accessibility Service. Clicking on the only button in that window will open your device Settings where you'll have to find All in one Gestures under your list of accessibility services and activate it. Now return to the app, tap the button in the top-right corner of the screen and select the Custom Keys option. This will open a window offering you to create a Custom Key, so tap it and press the Bixby button, then press the Back button after Bixby launches to return to All in one Gestures. Doing so will fill the Key Code field in the app with "1082," so tap the option for adding the code, select the box that's adjacent to the Key Code, then tap the Search field in the newly opened Action list. Select "Voice Search" and you're done - pressing the Bixby button on your new Samsung-made flagship will now activate the Google Assistant instead of Bixby.
Both the Galaxy S8 and the Galaxy S8 Plus are launching worldwide on April 21, so if you aren't keen on using Bixby at launch, you can follow the method outlined above to remap that button to the Google Assistant or any other Android app on your device.