How can I recover my Outlook 2019 calendar and contacts?

Outlook2019  Windows 10Pro

I mistakenly deleted some files (from the Documents folder, I think) and after that my Outlook calendar and contacts were missing.  Strangely, I was getting "reminders" for scheduled events, but was unable to respond to those reminders.

[My Outlook email is linked to my gmail account. I usually delete my emails after reading them, so the fact that I have none in Outlook now doesn't seem like a problem to me.]

I save (backup) my .PST file everyday, so I have yesterday's .PST file; but I don't know how to use it to recover the missing data.

I tried the Support and Recovery Tool, but it was of no help. It said I was not qualified to do one of the choices, and the other choice appeared to provide some fairly worthless "log files".

A couple of years ago, I had a lost some Outlook data, and tried to recover by replacing the "current" .PST file with my backup .PST file; but that resulted in duplicate data and some other problems I don't recall. 

Is there a straightforward way I can replace my existing .PST file with my backup .PST file, and get back to where I was at the beginning of the day today?

Or even a not-so-straightforward way?