no guide needed, just keep one thing in mind, you don't want to add any mass to the cone.
so, this leaves you with a few options you can try out, but there is no real guide to doing this (optimal way to repair it would be a recone or new driver):
1) silicone or super-glue carefull put over the hole in small amount to seal it up but to not have ANY excess.
2) tape. Electrical would probably be the best tape to use as long as it sticks.
3) leave it. as long as the hole isn't tearing while playing there shouldn't be a huge diffrence, some yes, but not a large amount.