Nice and simple.
And here's the macro:
I fed in the data, set the column to be long enough (just in case) then split out the field on "/", then split the year from the time on the remaining \s character. I then used padleft to add leading zeros to those with shorter values, then merged them together in the correct format. Boom.
Everything's easier with macros.
Just like everything's better with chili pepper. What? Even chess? Yes. Chess is better with chili pepper.