Deleting Sounds from a Kit

Hi,

I created some new sounds and saved them to +drive.
On my new newly created patterns I want to use them. So I created a new project, saved an existing kit to another slot with another name. Now I want to delete some sounds I don’t need and substitute them with my own sounds from +drive.
If a kit is full with 128 sounds it is not possible to add sounds from the +drive - i know - so how can i make space (delete sounds) from the kit pool? Is there a trick?

many thx