Samsung Galaxy S6 edge

Find "Import/Export contacts"

Press Contacts.

Find "Import/Export contacts"

Press MORE.

Find "Import/Export contacts"

Press Settings.

Find "Import/Export contacts"

Press Import/Export contacts.

Select option

Select one of the following options:
Copy contacts from your SIM to your phone, go to 2a.
Copy contacts from your phone to your SIM, go to 2b.

2a - Copy contacts from your SIM to your phone

Press IMPORT.

2a - Copy contacts from your SIM to your phone

Press SIM card.

2a - Copy contacts from your SIM to your phone

Press Device.

2b - Copy contacts from your phone to your SIM

Press EXPORT.

2b - Copy contacts from your phone to your SIM

Press SIM card.

2b - Copy contacts from your phone to your SIM

Press EXPORT.

2b - Copy contacts from your phone to your SIM

Press the box next to "Select contacts".

2b - Copy contacts from your phone to your SIM

Press DONE.

2b - Copy contacts from your phone to your SIM

Press OK to confirm.

Return to the home screen

Press the Home key to return to the home screen.