Welcome ENTPASS ! Forgive me for the negative tone of my post but I owe you an honest answer...
First, congrats on getting those tickets. The playoff round will be amazing - especially if Canada gets in.
As for exchanging...
I am not sure it matters who you use. There will be a ton of tickets available because, like you, many people will have paid a substantial price for their tickets, will do the math and think :
"I paid how much for a round robin game between Transylvania and Congo ?!?!?! Screw it... I'm selling them to recoup some of my investment."
Unfortunately, that will lead to a flood of ticket on the internet. Anyway, long story short, I've used Stub-Hub and the tickets sold - but be prepared for a bit of a haircut. Let us know how it plays out for you and how much you get. Good luck!