Sorry, I was thinking of the wrong form.
The T1032 Joint Election to Split Pension Income is part of your tax return, and will be sent together with the rest of your tax return forms. You can't use it to fix your over-contribution, though.
This CRA webpage explains how to deal with an Excess Contributions: https://www.canada.ca/en/revenue-agency/services/tax/individuals/topics/rrsps-related-plans/contribu...
