Break one link of multiple links within the same cell

Hello, I have a workbook that is linked to 8 different other workbooks. There are many cells within the multiple tabs in this workbook that are linked to these 8 various workbooks and I want to break 6 of them while keeping the remaining 2 each each corresponding cell that originally had the 8 (or sometimes it is just 6, etc.).
so for example:

Currently have something similar to this in hundreds of cells within one workbook:
='[workbook1]sheet1'!AA15+'[workbook2]sheet2'!AA15+'[workbook3]sheet3'!AA15+'[workbook4]sheet4'!AA15+'[workbook5]sheet5'!AA15+'[workbook6]sheet6'!AA15+'[workbook7]sheet7'!AA15+'[workbook8]sheet8'!AA15

Need to have:
= 500++'[workbook6]sheet6'!AA15+'[workbook7]sheet7'!AA15+'[workbook8]sheet8'!AA15
Where 500 equals the value of the 1st 6 workbooks (not always in this order by the way) = '[workbook1]sheet1'!AA15+'[workbook2]sheet2'!AA15+'[workbook3]sheet3'!AA15+'[workbook4]sheet4'!AA15+'[workbook5]sheet5'!AA15+'[workbook6]sheet6'!AA15

Is there anyway to do this aside from manually going into each individual cell and adjusting it?

Thanks!
Kyrsten

Try breaking the links to the files. Go to Data ribbon, click on Edit Links, click on the filename then click Break Link. This will turn all data from the linked file into values.

Sorry - that's above my pay grade I'm afraid. Good luck with it.