Hello @Carlosroth 

You can do that by making an extra KPN ID with a different e-mailaddress and then adding one of the subscriptions to the new KPN ID in MijnKPN.
That subscription will then automatically be removed from the original KPN ID.

You can do that on the website or in the MijnKPN app, to manage 2 MijnKPN accounts it's probably easier to do it on the website: https://mijn.kpn.com/