There is info on the Vicroads site, you may have to search the site to find the documents though.
Essentially though, you need to meet the following requirements:
Be a member of a club that's signed up to the club permit scheme.
The car must be at least 25 years old.
If the car was made after 1948, you need a current roadworthy certificate when you apply.
If the car is modified beyond what Vicroads allows under VSI8
https://www.vicroads.vic.gov.au/safety-and-road-rules/vehicle-safety/vehicle-standards-information then the car will need a VASS certificate, and will end up being issued with M (modified) club plates, rather than the usual H (historic) club plates.
You need a receipt to show you own the car when you apply.
A representative of the club needs to sign your application forms.
When you renew the club permit each year, a club rep. needs to sign the renewal form before you post/hand it back to Vicroads.
There are a few forms to fill out when applying, but once you're on the scheme things are pretty straightforward.