See the attachment. Here's how it works:
1. "Save Data" in TSB tool from your rom as a .csv file
2. Open the .csv file in Excel and copy everything (easiest just to click on a cell far away from the data, like O6 or something, and Ctrl-A to select all cells)
3. Select cell A1 on the "Paste_Edit Here" sheet of my workbook and paste
4. For players on offense, change only the attributes on the "Paste_Edit Here" page. It will automatically apply the sim value on the "Output" page
5. Copy rows 25-1003 on "Sheet 2"
6. In TSB tool, highlight everything from the "TEAM = bills..." line to the last line of the falcons roster, and paste over it
7. Apply to rom and you're done
I didn't touch the defense ratings because they aren't based on the players' attributes. You'll have to change these manually to determine the amount of sacks/interceptions players will get relative to others on the team. Any changes made to the "Paste_Edit Here" page update on the "Output" page, which will in turn update "Sheet 2". Also, any team ratings need to be changed in TSB tool, and it will only work on rom with 28 teams or fewer. One cool feature is that duplicate numbers on the same team will highlight red.
Lastly, for some reason all the formations are set to 2rb,2wr,1te even though I included data from the original rom. I'm not sure what's going on with that, but just keep in mind that my forumlas differ for RBs, WRs, and TEs. You may have to account for this or else you can end up with cells having errors or inaccurate sim ratings if you change the formations. Fixing it is as simple as a copy/paste, though.
Like I said, it's not necessarily finished or perfect, but you'll get the idea. The formulas are very simplistic and really account for only one attribute (except for the QBs). I simmed a few seasons on the original rom and the results seemed relatively close to the original so it's good enough for me. Feedback is welcome, or you can take it and change it to suit your own needs.