Connect a cable from your iPad to a Mac (or PC) and let iTunes open automatically.
Read all the messages from iTunes so you don’t update the ipad or sync it.
Click ‘cancel’ if it asks you to update.
On ipad you need to click ‘trust this computer’
Then, follow these instructions:
Select your device in iTunes (there will be ipad icon on top somewhere),
Select “App”,
Scroll down to see the “File Sharing”,
Select “Explain Everything”,
Select these projects, that you want to save on your computer, and click on the “Save to”,
Choose the desired location (create folder ahead of time or using windows features, seems it does not let you create new folder while saving)
Restoring presentations:
I deleted few presentations from the ipad, and to restore go to the same place in iTunes and instead ‘Save to’ choose ‘Add File’ and chose which files to add, on ipad the app needs to be closed (with a swipe after double-clicking home button) and reopened again to see the added files.