Please follow the steps below to replace a text string that matches the entire cell contents with case sensitive:
Step 1: Click anywhere in the worksheet;
Step 2: Click the "Home" tab from the ribbon;
Step 3: Click "Find & Select", and select "Replace" from the drop-down list;
Alternatively, please use shortcut Ctrl+H to bring up "Find and Replace" window.
Step 4: In the "Find and Replace" window:
1. Type the text string (or any letter or number) you want to replace in the first box;
2. Type the text string (or any letter or number) you want to replace to in the second box.
3. Click "Options" and then check "Match case" and "Match entire cell contents".
Step 5: Click "Replace" at the bottom to replace the next record; or click "Replace All" to replace all the records in the worksheet.