Open the Remix app in the web browser that you are using MetaMask with. Next, click on the file icon to create a new file. You can call the file “TockenUnlock.abi”. Confirm by hitting enter.
Next, copy the code from Edge & Node team member Abarmat that he published on GitHub. You can then paste the code into the TokenLockWallet.abi which you have just created. Make sure there are a total of 605 lines of code.
In the next step, click on the ETH symbol you can find on the left-hand side. This will forward you to the page where you can deploy & run transactions. Over there, select “Injected Web3” as your environment.
This will prompt a MetaMask message asking you to connect your wallet. Select your beneficiary ETH address, click on “Next” and “Connect” to connect your wallet.
Once you are connected to MetaMask, you can paste the vesting contract address you copied earlier into the “At Address” field. After this, click the “At Address” button and confirm the message that pops up by clicking “OK.”
After having added the vesting contract address, you can scroll down to the section “Deployed Contracts.” Expand the section and scroll down to where it says “withdrawSurplus.” Here, you can insert the amount of GRT you want to withdraw with 18 decimals at the end.