You will need to file an adjustment request for the T1135.  Please see the following FAQ for instructions on how to submit an adjustment request.

https://turbotax.community.intuit.ca/replies/2647992

Following the directions in this link, I worked through the 2018 ReFILE process, but in the final step TurboTax advised me my T1135 amendment must be filed separately from my federal return. At that point I was unsure how to proceed to completion. Can anyone advise how to do this please? Can it be done using TurboTax? 

Please go back to File>CRA Online Mail and click Continue until you get back to the page where you can send your return. There is a separate button to send the T1135.

I tried to refile 2019 just now which did include an updated T1135.   Since the original return had an amount owed, not sure how to proceed a it kept asking how I was going to pay CRA.