How to delete a group member

Hi!

I've made a group from multiple interconnect PCB-s (I've made the block artifact of the pcbs first), and I'd like to achieve that the floating type connectors of the PCBs are attached in the group with datasets already applied (like this if I have to use a PCB multiple times in a design I don't need to add the connectors every time one by one, and add datatables to them one by one...). It's working fine now but if I don't need one of the connectors in an assembly I'd like to delete it, so it doesn't appear. Unfortunately I couldn't get this done.
Please help me how to do this!

Thanks!

Laszlo