How can you change the renderer in Unreal after instaklling the unoffical 227f patch?

You have to enter the advanced options dialogue window via the main menu.
Alternatively, there are *.ini files you can edit in the game's /system directory, but this shouldn't be necessary.
Edit: note that the advanced options should pop up in a small window. On my computers at least, you'll be sent back to your desktop with Unreal itself also shown a window in the background while the advanced options panel is displayed. Find the entry for renderer: it should offer a drop down list with options.

Thanks, got it. =)

My pleasure! Glad it worked.