Can't install Updraft plus plugin

I’ve inherited a wordpress site that didn’t appear to have any form of backup.

I purchased Updraft Plus yesterday and am attempting to install it today.

I uploaded the plugin and it stuck at ‘unpacking plugin’. I checked the filesystem and can see an existing set of folders for Updraft that contain old backups, so it looks as if it was once installed but is no longer visible in the plugins interface. I’m assuming this is whats preventing the installation of the paid version.

The folders I can see are
/wp-content/updraft
which contains a couple of old backups and some log files

/wp-content/plugins/updraftplus
which contains 4 directories, which I assume are the plugin itself.

What I’d like to do is safely clear out this old version and install the paid for version.

Given that it’s not visible in the plugins interface on the wordpress site itself I’m assuming I’ll have to do this manually. I imagine that process involves

1. Delete Folders
2. Remove entries from the database

I’m happy deleting the folders but can someone direct me to how to safely clean the existing Updraft entries from the database?

I’m also open to suggestions if completely removing it in this way isn’t the best way forward?