The full download link for the current v2.11 is https://download.mikrotik.com/swos2/css ... 6-2.11.bin

To get an earlier version, simply edit this URL and change 2.11 to 2.10, 2.9 etc., whatever you require.

What is the method to update these?

I don't see an upload section anymore??

There is an 'Upgrade' tab rightmost on the interface.
Scroll to the bottom of this upgrade page for the option to manually upgrade the firmware.