Convert string date with three letter month to proper date format

Hi,

I have a data set with state and end subscription dates that are stored as text. I am trying to convert the text to proper date format.

The issue is that the day of the month dates aren't always two digits. For example, I have both

Jun  3 2016 01:06:10:900PM

and

Apr 29 2016 08:23:35:490AM

I would like to eliminate the time stamp altogether and convert just the date to a proper YYYY-MM-DD format.

I have been playing around with this for a little while and need some help! Original file attached. Thank you!