cannot delete from table service without cascade

Hi,
i have problem with my project,when i wanna delete service it does not allow me to delete.
Lets take example:
have many services/items to sell, i created orders and invoices for items that i sold but now i dont have anymore service1 in my shop to sell.
when i wanna delete that service i cannot.
is there any way to delete obsolete services but to stay in orders and invoices that are already created?
i know i can delete if i make cascade delete but then deletes all services from already created invoices or orders.
Thank you