...
make work
You can also add the key '-j4' to use 4 cores in parallel:
make -j4 work
3) Modify the source code
Once you set the environment the variables $gemdyn and $rpnphy will get set, pointing to the source code in the environment:
${gemdyn}/src/*/*
${rpnphy}/src/*/*
You can check there which routines you want to modify. Once you know which routine(s) you want to modify go back into your "executable directory". Then "check out" all the routines you want to modify with:
rde co subroutine.F90
or
rde co comdeck.cdk
You can also check out several routines at the same time.
Once you modified or copied the routines you want you need to compile them and then recreate the executable, following points b) 2) to 4) above.