# Replace Mode
The Replace mode is the default binding mode in froggr. It completely replaces whatever was previously mounted at the mountpoint with the new source.
## Usage
```shell
frg bind src mountpoint
```
## Behavior
The `src` completely overrides any existing content at the `mountpoint`. After the bind operation, only the contents of `src` will be visible at the specified mountpoint.
## Examples
### Replacing Configuration Directory
Temporarily replace a default configuration directory with a test version:
```shell
frg bind /test/config /etc
```
After this command, processes will see `/test/config` contents instead of the original `/etc`.
### Custom Toolchain
Redirect access to `/bin` to a custom toolchain directory for development:
```shell
frg bind /custom/tools/bin /bin
```
This replaces the system binaries with your custom tools.