Remove "Don't Know" values and recalculate remaining cells

Have a worksheet that consists of the automatic Excel output from survey responses. Some of these responses are identified as "Don't Know". I would like to remove the "Don't Know" responses and recalculate the percentages in the remaining columns, using the new total responses, for each question that has "don't know" responses.

A sample spreadsheet is attached with examples of the types of questions and output that might appear in the worksheet. In the real worksheet, there also are questions that don't have "don't know" responses and need to be ignored.
Sample data for DK responses.xlsx

I'm using Excel 2007 and have used macros before, but don't know VBA and am hoping that someone can help, as there is quite a bit of data. Thank you!