When I took it, it was frowned upon to go to a different tutorial. They'd let you if it was a one-time thing, say you slept in one morning accidentally or had an appointment, but not if it was every week. If everyone who had an 8:30 test decided to go to the 10:30 slot, for example, there wouldn't be enough computers in the room for everyone to write the test, which isn't fair to the people legitimately registered in the section. It might depend on the TA and how strict they are, but if this becomes a problem, they'll probably become much stricter about going to your assigned time slot.
If you want to switch due to a legitimate conflict, email the course coordinator--you can do this after class starts. When I took the course, it was Adrienne (
http://www.science.mcmaster. ca/kin...0Tearle.htm l) but I'm not sure if she still does it, so wait til the first day to make sure.