Please do not use patched browsers or backdate your system to use flash in a browser. This is not a good idea. In fact, it's almost a surefire way to get your system compromised.
Instead, follow the instructions in the opening post and use the stand alone flash player, which continues to work beyond the date. Also, be extremely suspicious of any flash files released after this date. They are highly likely to be malicious, and should not be executed, even using the stand alone player.