So, here is the issue, I am switching to protected content

So, here is the issue, I am switching to protected content completely, and as you know I have to import users one by one. The issue i have is that my site was free the first year of existence, resulting in me having several thousand members who are not assigned to any membership level. I need to delete these users in order to make this protected content switch somewhat reasonable. I have been going through the process of making all non-paid users in membership inactive. Is their anyway to bulk delete inactive membership users from the user list as i can't sort them in the user list and there is no delete button in membership user list? This would be a HUGE help is someone could think of a work-around. The rest of protected content is pretty much set-up at this point and I deactivated it before re-activating membership in order to achieve this. Site access is already granted b/c of previous issue if you need it.

It would even be great if there was a previous version(no matter how old) of membership that I could install that allowed deletion of users from the plugin member list if you could tell me the version number
Thank you