Dear Laura, As far as I know, you would still use the form for modification. After all termination of alimony is a modification -- a change. From instructions for Form 12.905(c:
"This form should be used when you are asking the court to change a current court-ordered alimony obligation. The court can change an order for temporary, permanent periodic, durational, and rehabilitative alimony if the judge finds that there has been a substantial change in the circumstances of the parties. Lump sum and bridge-the-gap alimony cannot be modified".