Barbarian's Intimidating Presence

[caseybcrocker]

I'm a DM and I use the optional skill rolls when it seems most reasonable (i.e., strength based intimidation over charisma based intimidation for a 7' goliath barbarian).

I've changed the skill base through a permanent adjustment, but how do I change it for Intimidating Presence DC? Can I?

To be clear as to what I'm asking for help on: the DC for Intimidating Presence is charisma based and I'd like to make it strength based.

Thanks for your help! This forum has always been so helpful!