Incremental find and replace

Hello, I have a large group of cells that I need to change. The first cell of each row for table a needs to be changed to match with the first cell from table b. Unfortunately for each single row in table b, there is a variable number of rows in table a that need to be changed to match, so I can't just do a simple copy/paste. What I'm looking for is some way to automatically go through and change all of them, since there are far too many to do by hand.

I don't know anything about Access scripts/macros, but what I am thinking it needs to do is start with a pair of values, one that needs to be changed and one that it needs to change to, and then loop, increasing these numbers by 1 each time until it gets to a defined number.

Here is a quick example. The numbers in column a of sheet 2 need to be changed to match the numbers in column a of sheet 1. All instances of the same number in sheet 2 need to be changed to the name number from sheet 1. For example, in the attached spreadsheet, all 9 cells that are 181939 in sheet 2 need to change to 192956 to match sheet 1, then all the cells that are 181940 need to change to 192957 etc.

To do this by hand would mean changing several thousand cells, which is why I came here hoping for help. The original information is in access, but I can copy/paste into and out of excel if that is easier or needed.

I appreciate you taking the time to look at this for me.

Yes to both questions. Thanks again!