Formal Letter & Data Processing -- 2

I have a spreadsheet of raw records that first needs to be cleaned, reorganised, and checked for consistency in Excel / Google Sheets. Once the data is tidy, I want it merged into a professionally formatted, fully Bahasa-Indonesia “surat resmi”.

Here is the flow I have in mind:
1. Process the data: remove duplicates, standardise names, fix obvious entry errors, and add any simple calculations I mark in the sheet.
2. Build (or refine) one master letter template in MS Word that follows a formal Indonesian business style—logo, reference number, date, subject line, structured body, signature block, and all the usual formalities.
3. Use mail-merge (or an equivalent Sheets add-on) so every cleaned row becomes its own finished PDF letter, ready to be sent. File names should follow the pattern “Surat_[NamaPerusahaan]_[Tanggal].pdf”.

I will supply:
• The raw spreadsheet (xlsx)
• A rough draft of the letter’s wording

I expect back:
• The cleaned and annotated spreadsheet (xlsx)
• The final Word template (docx)
• A folder of generated PDFs, one per record

If you have a quick question about the dataset structure, let me know before starting so we do the processing only once.