Need help ASAP! Tall Boot fit

I have never shown, but I am on my school's IHSA team this year so I ordered tall boots. They were supposed to come in more than a week ago, but they just came in today. We leave for TN at noon tomorrow and I show on Saturday.
So now breaking in is a problem. I've been wearing them since about 1:30, walking around in them and stuff. I plan on wearing them for the rest of the day (and may even go to gym on campus and walk on the treadmill in them if I need to!). They are starting to fit better around the ankle and don't hurt quite as much when I push my heel down, but the part around the knee is TIGHT. I can still feel my feet and everything so it's not cutting off circulation, but it pushes into my skin and makes the fat/extra skin around my knees bulge over the top (NOT pretty lol). What can I do about this? I'm praying they're the right fit, they were the only decent boots I could find in my budget. I'm only showing for a year, then hopefully transferring up north where I won't be riding at all, so I didn't want to spend 300+ on boots. Mine were 180, I think. Ariat Challenges. Thanks guys!

If you can get them to a shoe repair place, they may be able to stretch them a bit. It's worth a try.

As I started riding more, my calves got pretty muscular so I put in some elasticy pieces at the top (Or rather my shoe repair guy did) and that helped loads. Maybe that would help in your case too?

AllisonFinch: I don't think I have time to do that before the show :/ but possibly afterwards, how much would that cost?

Spastic_Dove: They have elastic on the insides at the knee. Maybe I just need to lose weight, haha!

Update: I did the water trick on the tops (put them upside down in warm water and then wore them until they dried) and it worked pretty well. I was comfortable in the show. They were really slippery and I couldn't get my heels down properly, but the calves were fine. I'm going to wear them in lessons now until they're nice and broken in before the next show. I didn't do very well in my class, but that's because I rode horridly. The team did very well overall though and one of our riders got reserve high point rider! So overall a successful show. Thanks for your advice!