Makefile for compiling AMET v1.4 combine, bldoverlay, sitecmp, sitecmp_dailyo3

I am aware that this topic is similar to the one posted before. But as I have not understood the solution , I need help in this regard. What are the changes to be made in the Makefile of combine, bldoverlay, sitecmp, sitecmp_dailyo3 for compiling them using GCC and Gfortran compilers.
Need the solution urgently.

Have you followed the quickstart or tutorial instructions for installing AMET?

If you are having trouble using Make to build combine, you may not have installed the Tier 2 software correctly.
If that is the case, you can review the instructions available for building those libraries (I/O API and netCDF) that are available in the CMAQ Tutorial instructions.

Thank you Sir. I have rectified the issue.