Install patch BEFORE creating databases | Data Conversion

Install patch BEFORE creating databases

Hi. On a Solaris 10 Sparc 64bit system, I did a "software only" install of Oracle 10.2.0.1.0. Now I'd like patch it to 10.2.0.3.0. But how do I do that? I ran "runInstaller" from the patch and pointed it to the directory where I installed the Oracle 10.2.0.1.0 software. But then I get an error message telling me, that there already is such a directory.