Head into Native Access and you should see an update option next to SPECTRES.

If it is not there, first try logging out of Native Access, exiting and rebooting, then logging back in.

If you still don't see the update, try updating Native Access. Make sure to install afresh from this link because NA doesn’t auto-update between major version numbers.
https://www.native-instruments.com/en/specials/native-access-2/

If all else fails, simply reinstall SPECTRES and it will install the latest updated version.

The latest version is 1.1.0

On this occasion, it was not possible to incorporate importing your own samples for SPECTRES. At the moment we do not know whether it will be possible to implement this functionality in future.

However, there is a vast and varied library of source material creating endless possibilities in sound design, which we consider to be the bulk of the value. We've had users initially express concern about the lack of user sample support, but then come back to us later saying they simply don't need it!