the best way to approach these projects is to start building, and then working out how to get all the stuff into the PIC18F452 chip will start to fall into place.
basically, to get the firmware in…
build a JDM programmer (see Thorsten’s page on this… www.ucapps.de)
install ic prog onto your PC (again, Thorsten has made easy instructions on his website)
burn the bootstrap loader (mios downloads page) into the PIC (Thorsten has instructions) using ic-prog
load the application into the PIC over a sysex midi connection, using “midi-Ox” (Thorsten…)
I think that’s it… If you have problems, we will help you out, but please put any programming issues in the relevant thread divisions