Pull the shirt over the tent frame and position it so the neck hole is in the front middle and the bottom of the shirt is trailing behind the tent frame.

Flip the whole thing up so the bottom is facing you and the hole is pointing upwards.

Fold up the excess from the bottom of the shirt and tighten it up so the neck hole is taut and safety pin the bottom in place. Then pull the sleeves tight and safety pin them in place too.

As you can see in the last image, it should be pretty tight over the frame. Keep tucking and safety pinning until it's ready!

(Yes, I know it would make sense to cut it, but I decided to leave it whole and safety pin it instead so it would be easy to remove and wash. :D)