> For the complete documentation index, see [llms.txt](https://gitbook.humanode.io/hmnd-ehmnd/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://gitbook.humanode.io/hmnd-ehmnd/hmnd-ehmnd-swap-guide/ehmnd-to-hmnd.md).
# eHMND to HMND
The guide to swap eHMND to HMND.
### Tools
* Environment to deploy ethereum smart contracts like [Remix IDE](https://remix.ethereum.org/)
* Ethereum supported wallet like [Metamask](https://metamask.io)
* [Polkadot.js apps](https://gitbook.humanode.io/docs/tools-and-services/polkadotjs-apps)
### Steps
1. Open the Remix IDE and create a file containing the currency swap precompile interface.
```solidity
// SPDX-License-Identifier: UNLICENSED
pragma solidity >=0.7.0 <0.9.0;
/**
* @title Currency Swap Interface
*
* An interface enabling swapping the funds from EVM accounts to
* native Substrate accounts.
*
* Address: 0x0000000000000000000000000000000000000900
*/
interface CurrencySwap {
/**
* Transfer the funds from an EVM account to native substrate account.
* Selector: 76467cbd
*
* @param nativeAddress The native address to send the funds to.
* @return success Whether or not the swap was successful.
*/
function swap(bytes32 nativeAddress) external payable returns (bool success);
}
```
2. Go to `compile` tab and compile the interface.
3. Go to deploy tab.
4. Properly select `ENVIRONMENT`, `ACCOUNT` and `CONTRACT` fields.
5. Use `0x0000000000000000000000000000000000000900` value as an input for `Deploy` tab at `At Address` field.
6. Click on `Deploy` tab and open `Deployed Contracts` tab. You will be able to see a `swap` call. The call accepts `bytes32` `nativeAddress` as an argument to send currency to.
7. Open `Utilities` tab at Polkadot-JS apps connected to Humanode Israfel Testnet.
8. Convert your native HMND address into `bytes32` value.
9. Copy the value from the `hex public key` field and go back to Remix IDE. Input the value as an argument for the `swap` call. Input the amount you would like to swap into `VALUE` field. Keep in mind, that you should input the amount with 18 point decimals value in case using `Wei`.
10. Finally, perform the swap by clicking on the `swap` call and confirm the transaction.
11. Check the balance on the Polkadot-JS app.
