Your data will occupy columns A, B and C (assume it starts on row 1).
In D1 you can add this formula:

= B1 + C1

to add the ranks together. To copy this formula down 7000 rows in one
simple operation, click on the cell then double-click the fill-handle
(the small black square in the bottom right corner of the cursor). You
might want to fix these values - click <copy as the range will still
be highlighted, then Edit | Paste Special | Values (check) OK and
<Esc.

You can then highlight all the data in columns A to D and Data | Sort,
choosing to sort on column D in ascending order.

Hope this helps - no need to pay!

Pete