how to delete unwanted rows after extracting top 10 values in excel


Hi,
I was wondering if there is another simplier approach to doing this as I need to extract the top 10 scores of students from each different groups , and then deleted the unwanted rows (e.g. 1th rows onwards).
Some of the groups, may have less than 20 students,though majority of these have > 20 in each different groups in rows and I have a numerous records to go thru such as attached..

Group Names ID Scores(Mean) Median Subject
1st.. A01


10th
11th
1st.. B02


10th
11th
... C03 .....
..........



Presently ,I first perform sorting by Group 1st, then by Scores( Largest to smallest) ,then goto each group in their first sorted row and manually numbered 1 to 20 in each group, and delete the rest of the entries in each corresponding group…So, if there is a faster way and efficient way via formula or VBA to perform this automatically…Please advise as i have quite a number of rewcords to do for the same steps....


Thks.
Regds,
Leonard
….