You could Google a copy of the Skype APK file, side-load it to your device and launch it from your file browser. This is assuming the Nextbook 8P is able to side-load and it has a file browser. You'll probably have to enable, somewhere in the settings on the device, the ability to install third-party apps. I don't have my Android phone with me at the moment, so I can't tell you where in the settings that would be.
Update: I've just noticed, Skype is available on the Amazon Marketplace
here. That's another option.