here is is how it is done on a paper wallet…it is for BTC but works the same for Litecoin Core Wallet.
On Litecoin Wallet QT
open the following
Open Debug Window
Then go to menu: /Help/Debug Window
Unlock your wallet
If your wallet is encrypted (I hope it is!) you must unlock it. If not just skip this step.
To do this just type into the box at the bottom:
walletpassphrase “YourLongPassphrase” 600
Note: The 600 means your wallet is unlocked for 10 minutes (600 seconds).
Run Import Command in Debug Window
In the console at the very bottom is a text entry box. In here enter:
importprivkey yourPrivateKeyInWalletImportFormat “TheLabelThatIWant”
You now have to be patient. On a fast PC it takes 2 minutes to import, and during this time it looks like you application has hung. After waiting a few minutes you will see:
p.s. it ‘always’ takes longer than 2 min stated above IMHO…just leave it alone and wait
Anyway …I have this Zeroxed along with my paper wallets something like above for reference you
swipe all funds out and then send/do whatever you need to do in the wallet. I then send any ‘change’
to a NEW paper wallet and file that back in the safety deposit box rinse/wash/repeat