CHARMM36m WYF parameters

GROMACS version: 2021.2
GROMACS modification: No


I currently use the CHARMM36m forcefield and want to test the CHARMM36m WYF forcefield for my protein system. I have looked into the main paper, which stated to change the parameters and gave an NBFIX file for the parameters to change. Question: Do I need to copy the NBFIXES into nbfix.itp and go into the ffnonboned.itp file and change the corresponding parameters? What if the existing atom type pair is not in the current ffnonboned.ipt file?

Thank you.