If you want to sweep paper wallet, it will request for transaction fee, but while do you not just import the private key into the wallet of your choice.
Perhaps he wants to move the funds to a hardware wallet or a HD wallet where he cannot import a private key. Or perhaps he wants to send some of them to another person, or split them up between multiple wallets. There are plenty of reasons to sweep an address rather than import a private key.
To convert private key hexadecimal to base58 WIF, use
https://bitaddress.org, click on wallet details, input the hexadecimal private key into the space provide and click on view details. You will be able to convert the private key to WIF.
Except if you do this, you will have exposed your private key to the internet and instantly put your funds at risk.
You need to use an offline computer, preferably a permanently airgapped one with a clean OS, import your private key there and sign a transaction on this airgapped computer, and then move the transaction to an online computer to be broadcast. There's a good post from LoyceV about this here, which I'll just link to rather than re-hashing all the information -
https://bitcointalk.org/index.php?topic=5318475.msg56389821#msg56389821