Deleting earlier Kernel Versions

[Betti Ann & Preston Smith]

Good day all!

AS my system is updated I notice from the GRUB menu that I now have a 
total of four kernel versions on my system

How do I go about deleting the earlier versions and totally removing 
them from my system?

When I delete a kernel is grub updated or do I have to manually do the 
update?

In the Grub menu I default to XP so that my wife will always have her 
O/S of choice.  Presently after each update I increment the Default 
statement by 2 to keep XP as the default.  Is there a statement other 
than Default that I can use so that I do not have to manually intervene?

Thank you and enjoy the weekend.

Preston