How to add Hoenn World map into Fire Red?

I am looking to add the Hoenn world map into Pokemon Fire Red. I'm trying to replace the Islands with the Hoenn maps so both Kanto & Hoenn are active and able to be reached with fly. If anyone has any tips or even wants to help me do it, the help would be much appreciated.

The Hoenn map has a wider cursor range than the Kanto & Sevii maps. Also, it is in 8PP while the latters are in 4BPP. You will have to re-color the Hoenn map in 16-color and divide it into at least 2 parts to fit in the Sevii map slots.