How to remove old licenses

Use fw printlic to view the current license situation, and then re-enter your current license string (eval or permanent key) with a -o option. This will overwrite all existing licenses.
fw putlic -o ...

message "to many hosts", what shall we do to unlock the situation

To remove firewall license limitation use the procedure:

fw lichosts
rm $FWDIR/database/fwd.hosts
rm $FWDIR/database/fwd.h
fwstop
fwstart