3 Answers

Start here my friend...https://support.apple.com/en-gb/HT201541

Click on the apple ikon in the top left of your screen. On the drop-down menu, click on 'About This Mac' which then opens a window showing an Overview of your Mac. This shows which version of Mac OS X you are using. On the bottom of this window, click on Software Update. A new window opens to show what Updates are available. Then it is simply a matter of selecting which updates you wish and clicking on the install button.

In a nutshell, that's it.

Caliber Oris 771Functions Centre hands for hours link minutes and chronograph link 14 seconds 2 subsidiary dials for continuous seconds and link 30 30-minute counter fine timing device and stop-secondDiameter 30mmPower Reserve 48hWinding AutomaticFrequency 4HzJewels 27