Since 1.0 came out many have been having trouble with both Safari Enhancer and Safari Aquafier to remove the metal interface of Safari. The guy who makes Safari Aquafier e-mailed me these manual instructions for aquifying Safari if none of the software works. This is pretty simple, you just need developer tools installed.
Open the Applications folder and Control+Click on Safari.app. Choose Show Package Contents.
Open the Contents folder, then the Resources folder. Next, open the .lproj folder for your language. Find the file Browser.nib. Open it. Press Ctrl+Shift+I and uncheck the Textured Window option. Save the changes. Now, open the Downloads.nib file from the same folder and do the same thing. Then re-open Safari.
Have fun.
Open the Applications folder and Control+Click on Safari.app. Choose Show Package Contents.
Open the Contents folder, then the Resources folder. Next, open the .lproj folder for your language. Find the file Browser.nib. Open it. Press Ctrl+Shift+I and uncheck the Textured Window option. Save the changes. Now, open the Downloads.nib file from the same folder and do the same thing. Then re-open Safari.
Have fun.