To widen that main bridge will have major service disruption on the rail corridor.
From drawing I have seen, only the south ramp bridges were to be remove and a one built to bring the road down to the new Fort York extension level.
To widen the Main truss bridge will require all floor deck beams (east-west) to be removed all at the same time as well at the top along with bracing. The main support trusses have to be shore brace while the support beams are removed and then have to be move to the new support piers. Support shore bracing still has to be in place to hold the trusses in place until at least 6 main deck support beams (east-west) and the same at the top are in place to hold the trusses in place before bracing can remove to eliminated the impact on the rail corridor.
Since this is a live action area, most steel work will take place at night with some during the day.
Rail tracks can be move to the south end of the bridge for the Lake Shore line, but will be a tight turn for the other lines. Train service will not be reliable during this time. This after the existing ramp section is remove.
Since this bridge was built using rivets, it will take extra time to remove the connections. Using today bolting system, it will take less time to install the new steel.
I sure this is only for the south end, not the main truss. A good coat of paint will have the bridge looking good.