how to install membership plugin overtop of the lite version?

when I try to upload the full/paid version of the membership plugin it fails as the directory already exists. I presume the failure is because 'membership lite' is already there using a directory called membership.

How exactly should I be installing this as when I tried deleting the folder, then uploading the full version, the plugin would not block paid content from anonymous members.

I have reverted to the 'lite' version for now and blocking paid content works again.

Any ideas?