Currently running El Capitan, 10.11.6. I want to install Sierra on an empty partition on my external HD. I have downloaded Install MacOS Sierra, 12.5.3 and ran that which resulted in a folder, MacOS Install Data, being installed on the empty partition. After that folder installed I got a message to restart my computer to complete installation. I assume that would work if Sierra was installed on my startup disk but it's on a separate partition.
How do I complete the installation of Sierra on the external HD partition?
Thanks.
