I don't think you can? You might just have to cooperatively close it and reopen another if it's that there's less than ~600 Satoshi in your wallet?
But youll need around 0.003 to open a new channel.
Sent test 0.0001 to one and the second wallet to try out LN.
Later on the site it turned out that the minimum need is 0.002 per wallet. Why do you say 0.003 is the minimum?
Something very expensive turns out to use LN. It's easier for me to wait for the hype to subside and then send 1 Satoshi \ bytes the old-fashioned way from the blockchain.
Why is that? After all, LN is designed to increase the speed and reduce commissions on transfers