In order to compile thermo_pw the main Makefile and the files install/makedeps.sh and install/plugins_makefile of QUANTUM ESPRESSO need to be changed. In the thermo_pw directory give the command make join_qe. This command exchanges the files contained in thermo_pw with those of the QUANTUM ESPRESSO package.
Typing make thermo_pw from the main QUANTUM ESPRESSO directory, or make from the thermo_pw directory, produces the executable thermo_pw/src/thermo_pw.x that can be found in the QUANTUM ESPRESSO bin/ directory. A few other tool codes are produced as well and linked in the bin/ directory of QUANTUM ESPRESSO.
thermo_pw has been written on a PC with Linux operating system using the gfortran compiler with openMPI parallelization. It has been run in parallel on a Linux cluster with several hundreds processors. It has not been tested with other combinations of computer/operating system, but it is supposed to run on the same systems where QUANTUM ESPRESSO runs. If you have a machine in which you can compile and run QUANTUM ESPRESSO but not thermo_pw, please report the problem.