simple answer: you don't.
wdym "clash".. you should keep both UIs in 2 different folders so you don't mix them up and give yourself problems
since new ui items have been added to the epw ui since i had my custom one made i cant put it on anymore so i wanna know the xtml or w/e else files could be added/clashing with what needs to be there so i can fix it and use my ui again