One section in the first set of alternate notes seems to shorten the tune by a measure. I don't know if what I did with the notation is the best way to show this, but I couldn't think of anything better.
There are three titles in the Register that begin "Ich weiß, daß mein Erlöser lebt": "Ich weiß, daß mein Erlöser lebt, ob ich," "Ich weiß, daß mein Erlöser lebt, ob schon," and "Ich weiß, daß mein Erlöser lebt, Trotz." I'm not sure which one this is, although it seems to be drawn from part of Job 19:25 ("'I know that my Redeemer lives'").