One of the easiest method to install a third party bundle is to use esxcli. Discovered this while trying to install bnx2 driver.
This bundle was installed on a 5.1 GA machine.
~ # esxcli software vib install -d /vmfs/volumes/Softwares/BCM-NetXtremeII-xx.0-offline_bundle-xxxx.zip
Message: The update completed successfully, but the system needs to be rebooted for the changes to be effective.
Reboot Required: true
VIBs Removed: xxx
~ # reboot