How to merge this codes

The first coding file name:
Arduino_MARG_GY-85

The second file name:
DIY_headtracker

The file is in the Attachments.

Please HELP!! This is my Graduation Project.

Arduino_MARG_GY-85.ino (4.79 KB)

DIY_headtracker.ino (31.9 KB)

Functions.cpp (8.81 KB)

Functions.h (393 Bytes)

Sensors.cpp (21.3 KB)

Sensors.h (928 Bytes)

Config.h (2.58 KB)

Read this Merging Code

Also see THIS Page