First, It must be a coupled return and both returns have form T1032 already. In form T1032, please select the option to indicate who is pensioner or pension transferee. Additionally, if total sharable month is not full year, please enter the number of month on page 1 of form T1032.
Second, choose menu "optimize | optimize return". Optimize will identify sharable pension for split. Press "Optimize" button, then it will calculate a best split. On the best split screen, you can easily change the split pension amount to get different result.