Holders of the initial ERC20 TRX tokens that were distributed after the end of the Tron ICO back in September 2017, will have to go to exchanges that offer permanent token migration to the Tron Mainnet for the converstion of the tokens to the TRX coins on the Mainnet. This is after the Tron Foundation shut down its website’s ERC20 wallet withdrawal and consultation service.
Initially, the withdrawal service was closed on the 22nd of June 2018. This was after the successful launch of the Tron Mainnet on the 25th of June. However, due to users still having doubts about ERC20 tokens and those on the mainnet, the consultation service was extended twice. The first deadline had been set for the 1st of January. This was then changed to the 31st the same month. It is on the latter date that the service was officially closed.