Rusty T

First off I want to thank everyone at OSXLATITUDE for ther work! I have successfully installed Lion on my D630. I would like to change my trackpad kext but I am afraid of messing up my install because I'm not sure how to rerun the EDP and only install one kext. Should I remove the old kext first? Do I install everything again with a different option for trackpad? Do I run Myfix after? If someone could explain the correct procedure that would be great. Thanks again. Rusty