It's a long walk but yes you should be able to do it, just need to work out which end of T2 you arrive at. If you arrive to a gate with a number higher than C6 or D6, you'll need to follow everyone else towards arrivals and then keep walking straight when they all turn off to go to immigration. If you arrive at C1-C5 or D1-D5 then turn the opposite way to where everyone else is going. The ground staff may try and redirect you but you should be able to explain what you're doing. I can't think of any reason why immigration wouldn't let you through either. I haven't taken the Skytrain airside so can't comment on that.