Prior to vSphere 6.5, AutoDeploy and Image Builder sevice can be executed by VMware PowerCLI only. Now you can build a custom image within the vSphere Web Client. In following demonstration, I was able to add custom drivers and remove drivers from the original VMware ESXi 6.5 ISO. Finally one new custom image was created then exported as ISO.
Firstly you need to start the ImageBuider service manually in vSphere Web Client, go to Administration > Then at System Configuration click Services > Select ImageBuilder Service, click the Actions menu, and select Start. Then Auto Deploy GUI will visible in vSphere Web Client, both the Image Builder and Auto Deploy services must be running. You should have the ImageBuilder Service up and running.
Then clicks the Auto Deploy icon in the welcome page, go to Software Depots tab first.
Add a software depot first.
Then import VMware-ESXi-6.5.0-4564106-depot.zip (original vSphere 6.5 image from VMware website) into it.
Next import the new Emulex driver into it, then you can start to create new image profile.
Input name and description, then Next.
Choose the ipfc Emulex driver on Software deport menu and select it.
Select the VMware ESXi 6.5 zip you have uploaded and deselect the drivers you want to exclude.
Then clicks the Finish button.
The new ESXi 6.5 Images created.
You can generate ISO or Zip format.
Clicks that Generate image button to geneate new image.
Once completed, you can download this image.