To enter line 52 follow these steps to get back into your T4 slip form:
Click on the "Income" tab at the top of the screen.
Navigate to "T-Slips".
Select the "T4 Employment Income" option at the top of the list.
Enter the amount in the box labelled as "Pension Adjustment" with a blue box containing a 52 next to it. This items is 6 boxes down from the "Province of employment" box in the left column.
