Excel VBA Script to find a cell and replace a different cell with a value.

Hi Experts

I am in need of some help with a VBA script please.  I have a single workbook with a tab labeled "final".  

First thing I need to do is in Column "D" find two different values 123 and 456.  There will be no dupes and these are unique to that
column.  Find each of the values and change whatever value is in Column F (of the same row as the column D value) to 30-03-01.

Second thing on this same tab.  In column D find "BB1224" and whatever value is in column I of the same row subtract 30.  

Any help would be so greatly appreciated.

Andy