Brent is 100% correct and I have upvoted his answer. You should be careful to not make any changes via RDP to a production service. Having said that, you did mention that this was just for testing purposes during your development phase, and there is a lot of value in being able to update a single DLL file and test without having to redeploy the entire cloud service. I do this all the time when troubleshooting on an Azure VM.
Check http://blogs.msdn.com/b/kwill/archive/2011/05/05/windows-azure-role-architecture.aspx for the architecture of the processes on the VM. In particular, note that WaHostBootstrapper is the parent process for both worker and web roles. To replace a DLL in either web or worker roles the best method is to:
- Terminate WaHostBootstrapper. You can do this via Task Manager.
- Replace the DLL. Note that you need to be quick when doing this because Azure will automatically restart everything shortly after you kill WaHostBootstrapper*.
- Wait for WaHostBootstrapper to automatically restart, which will then automatically restart WaWorkerHost/WaIISHost.
*If you need longer time to make your change then you can attach a debugger such as WinDBG to WindowsAzureGuestAgent and leave it broken into the process. This will prevent Azure from automatically restarting the host bootstrapper process. After making your changes you can then detach the debugger and let WindowsAzureGuestAgent continue running. Note, that if you leave WindowsAzureGuestAgent in the stopped state for more than 10 minutes then the host agent will detect that the VM is unresponsive and reboot the VM.
*Edit: More detailed instructions are available at http://blogs.msdn.com/b/kwill/archive/2013/09/05/how-to-modify-a-running-azure-service.aspx.