To copy the schemas into a local directory, do the following.
cvs -d :pserver:anonymous@cvs.freehep.org:/cvs/lcd co lcdd cp lcdd/schemas/*/*/*.xsd /mySchemaDir
Then set the GDML_SCHEMA_DIR environment variable to point to this local directory.
GDML_SCHEMA_DIR=/mySchemaDir
SLIC also searches automatically in the current directory for schemas.
The entity resolver in GDML should find the schemas if the structure has been flattened, as in the above configuration.
If you want to keep the schema directory structure, use this command from your lcdd directory.
cp -R schemas /mySchemaDir
GDML should be able to find the schemas if the path component of the URL is preserved, i.e. /mySchemaDir/schemas/lcdd/1.0/lcdd.xsd.