I still don't understand why you want to shrink the log file. From what I've read the transaction uses 0.5% of the log so where is the problem? Is this a transaction that is a one off or does it run repeatedly? If it's a one off you are not going to free up much space and if if runs repeatedly then the log will grow again so just leave the log file alone.

Apologies if I have misunderstood.

Thanks