Problem setting the FQDNs

Hi, Right now we are installing from the beginning the Solution Manager 7.0 Ehp1 in Linux Oracle system (we had to uninstall our Solution Manager 7.0 because it presented some errors in its Java component), right now Our Basis is not available for like a month and we are having problems with the FQDN setting , We have read about setting the SAPLOCALHOSTFULL, SAPLOCALHOST and the icm/host_name_full, but we dont know where to set those and a step by step about this would be aprecciated.

Thanks for your answers

Paul