Mass remove contacts from a list, while keeping them on another list.

Mass remove contacts from a list, while keeping them on another list.

Hi commmunity!

We want to clean up an important list (list #1) of contacts while keeping them on another list (list #2). This way the import to the 'Do-Not-Mail'-list is no option, i think.

I want to make an export of the 'Never Opened' in 'Listbased Reports' and import them in a way to clean up list #1, but not remove them from list #2.

So how do i clean up list #1 while keeping them on list #2? 

Hopefully i can make my question clear this way. If extra information is needed, let me know. Thanks in advance!

- Wouter