Hi, Arturo,
As you know that the MC56F845xx and MC56F8444x are almost the same, the difference is the Flash size, RAM size, and the number of peripherals, so you do not need develop from scratch.
You can create a new project based on for example MC56F84565 on CW for mcu, then configure the PLL so that it can generate 60MHz clock. Then copy the code from original project to the new project, it is okay.
But it is difficult to extend a new SCI module.
BR
Xiangjun Rong