I am on vacation and left my phone at home and need a way to forward the calls and change my devices access code so my roommate can't use my phone while I'm away.
Device access code? Impossible to change without the phone. You could however remotely lock your phone if you have that feature already enabled on the phone. How will depend on the phone.
Call forwarding does require the phone. You could try calling in to Telus Mobility technical support and see if they can help but it's not likely.