I'm in the same situation, except that I have breakfast at CRT.
I've been told that you need to bring your PS with you and give it at the gate for admission.
From what I understand, boats to MK start running from WL at 8A. You didn't say what time your reservation is so I don't know if that is early enough. Mine is for 8:20 so it is probably too tight.
Before 8A, there should be busses to the TTC and then monorail to MK, or I have also read that boats to Contemporary start at 7A and then a walk or monorail to MK. I'm going to check with front desk when I check in as to the best way to go.