Google Sheet Data Corrections

I have an existing Google Sheet that’s already structured but contains outdated values. I need a meticulous clean-up: every record in the sheet must be cross-checked against a newer spreadsheet (in Excel format) and corrected where the two files differ.

Here’s what the job involves:
• Import or link the reference file so the two datasets align row-for-row.
• Identify mismatches in names, dates, numbers, and any other fields, then overwrite my Google Sheet with the accurate values from the source file.
• Preserve all formulas, formatting, and column order that currently exist; only the cell contents that are wrong should change.

A successful hand-off will leave me with:
1. The updated Google Sheet, error-free and fully functional.
2. A short change log (or a highlighted tab) that shows which rows or columns were modified, so I can audit the work quickly.

You may use built-in functions such as VLOOKUP, INDEX/MATCH, QUERY, or even Apps Script—whatever lets you perform the comparison reliably without introducing manual mistakes. Accuracy is more important than speed, but I’d like to wrap this up within a couple of days once we start.