I don't think you may keep exotic pets in Holland and to be honest with you and straight forward, it not worth the time and effort for you to export your spiders.
(Just from what I'm reading and what I know from imports one would have to Aquitaine your spiders.)
But if you really want to, you need to contact Natcon for and export permit and then you have to contact Netherlands to clear if you may import your tarantulas into Holland.
Some info I found on Google, scroll to the bottom of the page to international.
Ordinances Regulating Private Possession of Exotic Animals
Holland
It is illegal to keep exotic animals as "pets."
I have spent a couple of hours goggling and reading through pages of information and have not gotten much more info than the above bit.
Here is another story, ok, they tried to illegal bring them in
Dutch customs find hundreds of tarantulas
I think you need to contact the Embassy and talk to someone there.