Copy the pair of files ".c" and ".h" you want to use to the folder with your code.
Most modules need "config.h" as well - copy this one too. It contains the definition of CPU frequency - edit it to match yours.
Add ".c" file to your project
Add #include "file.h" to your main.c

UART (Serial communication):
There are 2 versions - without interrupts (UART0.c, UART0.h) and with interrupts (UART0_IRQ.c, UART0_IRQ.h).
You can use only one or the other, but not both at once. 
Baud rate is set in config.h

For LCD:
To use LCD functions copy to your folder:
   LCD_Ili9341.c
   LCD_Ili9341.h
   ugui.c
   ugui.h
   ugui-config.h
   config.h
add all ".c" files to your project. 
Add #include "LCD_Ili9341.h" to your main.c. All other ".h" are already included by "LCD_Ili9341.h", so there is no need to include them separately.
Call LCD_Init() after calling Init_IO().
Now you can use printf("Hello"); to write to the LCD.
All other LCD functions can be found at the bottom of ugui.h
