Newbie question; replace one locomotive in a session with another

[olsbyn]

Hi all, new player to Trainz 2019 here, not new to train simulators though
My question is simple..I think: I'm wondering how I can replace one locomotive in a session with another one, I'm aware of the placement via quickdrive, but I want to keep the tasks of a session, just run it with another locomotive than the preconfigured in the session, how can I accomplish this ?

 

[KotangaGirl]

You can do this by editing the session and changing the locomotive in the schedule.

 

[teddytoot]

Pause your session
Press 4 to go into free range mode
Select Tools Menu/Edit Trains
Using the Trains - Add train pop-out and make the change
Close the pop-out, click on the new loco, un-pause
And away you go

 

[olsbyn]

Thank you very much both of you, both answers are very usefull