How much would it cost to switch from active to passive (re-wire)? I'm gonna leave it to the experts because I don't wanna drill on my woods just to increase the hole for the pots.
Going from active to passive, it'll be less hassle than passive to active. It also means less costly compared to going active due to additions of parts/ features/ accessories. I'm not going to be precise here but these are the considerations cost-wise (because each store dealing with this will give you a different quotation):
*new pots (volume/ tone)- $8 per pot
*new capacitor for tone pot- $5
*new input jack- $12
*service charges- $48+/-
Cost for parts- depending on your preferred brands. You can consider used parts which are in good condition if you are game for pre-loved items (scout around- you might get good deals).
My Ibanez RGA32 here used to have active pickups, now it's sporting a pair of passive Duncans