One way to replace all instances of the word "Unknown" with the names of students in a computer science class in a spreadsheet is to use the "Find and Replace" function.
1. Select the column or set of cells that contain the words "Unknown" that you wish to replace.
2. Click on the "Find and Replace" button or use the keyboard shortcut (usually Ctrl + H or Cmd + H).
3. In the "Find what" field, type "Unknown" (without the quotes).
4. In the "Replace with" field, type the name of the first student in the computer science class that you would like to replace "Unknown" with.
5. Click the "Replace" button to replace the first instance of "Unknown" with the name of the student.
6. If the replacement worked as expected, click the "Replace All" button to replace all instances of "Unknown" in the selected column or cells with the name of the first student.
7. Repeat steps 4-6 for each additional student name until all instances of "Unknown" have been replaced with the names of the computer science students.
Keep in mind that the above process assumes that you have a fixed list of names to replace "Unknown" with. If you do not have a fixed list of names or if the names are coming from a separate document, you may need to use a different method such as merging the two spreadsheets or using a lookup function.