Upgrade from ESX 3i (3.5.0) to ESX 5i

Hello all,

I have a VMWare ESX Server 3i (Version 3.5.0, build - 123629) running on a server.

I whish upgrade it to the ESX last version. Can someone please help providing answers to these questions:

1. Is the upgrade from ESXi 3.5 to 5.0i free?

2. Is the license available for free or do we need to purchase a license for ESXi 5.0i? If it is free, where can we get it?

3. Would the upgrade impact/delete the VMs (GUEST OSs) running currently on the ESXi 3.5?

4. Can the upgrade be done from VMWare Infrastrcuture client 2.5 or do we need to download something else for the upgrade?

5. What is the upgrade process? Could someone provide a document?

Thanks a lot for the help.