Leveling and Removing Spells in a Spellbook?

[Zarathustra]

I'm working on a spell system for my campaign, and am running into a problem. Each character has 4 skill classes (spellbooks with different base order ID's). I set up the spellbooks themselves as hero skills with multiple levels. When a character gains a level, I add new spells through a disabled dummy spellbook. Here is where I run into a problem: Adding is simple enough, but how do I remove a spell?

For triggerd spells, I can check the level of the corresponding spellbook and add a bonus to the spell effect. Not all of the skills I have in these spellbooks are triggered, though. For example, I have 5 versions of plain old "siphon mana" corresponding to 5 levels of the skill. When the hero is level 1, level 1 mana burn is added. When the hero reaches level 3, I want to remove level 1 siphon mana and add level 2 siphon mana in its place. Is this possible, or do I need to just have 1 level of siphon mana and use triggers to modify the effect based on the level of the corresponding spellbook?

 

[Maker]

You can increase the ability's level inside the spell book directly.

"Unit - Set level of ability"

 

[Zarathustra]

Really? Wow. That was amazingly... simple. Thanks.