In standard situation update can be started by clicking on message box appeared after S32DS Launch:
If you don't see such message - you can check for updates/update your S32DS Installation manually. On main menu bar click on Help -> Install new software
Click on available sites, choose PEMicro and S32DesignStudio (you can also add IAR or Lauterbach sites), click on OK
In "Work with" row select All Available sites (or particular one which you are interested in) - if updates will be found - click on next. Some items may need to agree with license or certificate (new dialog will appear).
Download update package from Updated/Patches (for ARM S32DS - S32 Design Studio IDE for Arm® based MCUs|NXP - you can find similar section for Power and Vision S32DS too). Click on Help -> Install new software and choose Add -> Archive
Select update ZIP file and continue with Next button.