Some have trouble getting the update with mac app store so you can get the Sierra DP5 or PB4 via browser instead with these links:
DP5 update: http://swcdn.apple.com/content/downloads/16/29/031-71810/70rsu752vqfj8aaxj3qx2b1e5krs3wmt3z/OSXUpd10.12.pkg
DP5 Firmware Update: http://swcdn.apple.com/content/downloads/16/29/031-71810/70rsu752vqfj8aaxj3qx2b1e5krs3wmt3z/FirmwareUpdate.pkg
DP5 Full Bundle Update: http://swcdn.apple.com/content/downloads/16/29/031-71810/70rsu752vqfj8aaxj3qx2b1e5krs3wmt3z/FullBundleUpdate.pkg
Don’t just run the installers individually. They will stop you doing that with an error message.
For DP5, put them into /Library/Updates/031-71810 and restart. Then go to updates tab in mac app store and click update.
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PB4 Firmware Update: http://swcdn.apple.com/content/downloads/30/50/031-71809/623fo70n8d7eln9jd0exveumk7gg0f4ugi/FirmwareUpdate.pkg
PB4 Full Bundle Update: http://swcdn.apple.com/content/downloads/30/50/031-71809/623fo70n8d7eln9jd0exveumk7gg0f4ugi/FullBundleUpdate.pkg
For PB4, put them into /Library/Updates/031-71809 and restart. Then go to updates tab in mac app store and click update.