Change Xcode Paint Module

We have the open source paint module used in Titanium Developer (Appcelerator Mobile) which is being used in our app. The paint module works great and has the ability to undo paint strokes... however the method in which its been built only allows for about 150 paint strokes before the app receives a memory warning error, causing the app to crash. It looks like the complete paint stoke history is being added to an array... and eventually that array gets too large and the app gets a memory error. What we would like an Objective C developer to do is edit the Xcode project and modify the module to only allow for 20 paint stroke undos. So for example if they do 100 paint stokes... they can only undo to the 80th stroke.