Pull down a new source you can now change spell list of an NPC with ModifyNPCStat
example...
Code:
sub EVENT_SPAWN {
$npc->ModifyNPCStat("npc_spells_id", 3); #Spawn with spellset 3
}
sub EVENT_SAY {
#test swapping spell lists
if($text =~/spells/i) {
my $new_list = substr($text, 7);
$npc->ModifyNPCStat("npc_spells_id", $new_list);
}
}