How to delete all contacts?

[andsut]

On my Xperia xz2 I have stupidly merged my contacts from another with sd card. So the contact details on phone wrong but my Google account has not been effected so the contact details are correct, so wanted to delete just my phone contacts (all of them) 

[_alexdon_]

@andsut  on the older xperia devices, you could go to settings - apps and notifications, tap show system (3 dots in the right corner) and look for contacts storage. Clear data for the application.