Is there any easy way to exchange small amounts, a few dollars of Tron to Bitcoin or Ethereum?
Binance can do that even if it's just 3 dollars. Don't trade to BTC however like Bitmaxz just said. Ether is a much better option if you are planning to withdraw.
Binance's withdrawal fee is 0.01 ETH, if he has $ 3 and wants to exchange it to withdraw it I think he will lose 1 half of his money.
Is there any easy way to exchange small amounts, a few dollars of Tron to Bitcoin or Ethereum?
I can advise you to exchange yobit, Yobit's ETH withdrawal fee is 0.005 ETH, this is a good choice if you have a small amount.