Get one from my signature, which is located under this reply.
It's in a gray box called SPOILER: Recommended Injectors.
Additional injectors can also be found here, although the aforementioned "Recommended Injectors" are a few of the best injectors around.
What aero did not, however, mention is that you will also need the hack itself, a few of which are on this page.
Here's a mini-guide: >>Download the files (injector + hack)
>> Use Winrar/7zip to extract the files into a folder
>> Depending on the injector, you may need to open the injector and choose the hack or drag+drop the hack on to the .exe
>> Run CA.