I found a site 'vi/vim delete commands and examples' which has a great
explanation on how using variants of the delete command.
But what if you use relative line numbering in Vim?
':+13,$d'
This deletes from 13 lines below to the end of the file
Pointing to a line can be made relative by using a '+' (didn't try a '-'
but it should also work).
Awesome!
https://alvinalexander.com/linux/vi-vim-d
//meine