Changing date format in a text string

Hey all,
So I'm just a lowly intern who has been given the task of changing date formats in a bunch of spreadsheets. The string is as follows:

1015 Dixon Schwabl Est. for Creative Svcs 101207.pdf

I have to change the date at the end (mmddyy) so it reads as yyyymmdd. There is a long column of these strings, and i have to do it on over 300 spreadsheeys so if y'all could help me out I would be very appreciative. I have very minimal experience with excel and coding but can try to answer any other question you have.

Thanks in advance for the help!

Is there always a 3 digit extension at the end of the string? (i.e. Are they all .pdf)

Is the date always in format (mmddyy). Would January 1, 2007 be 010107?

Is the year always from 2000 newer or is there some in 1999 and older?

This worked perfectly on the first one I've done so far. Thank you so much!!!