Improve cheerleading stunts for tryouts?

Cheerleading tryouts are in four weeks, and I’ve been slacking off during the summer so I’ve lost a lot of my flexibility. I can’t do a scorpion or heel stretch anymore. I can get pretty close with my right leg, but all the stunts on my squad are left legged. And I’m one of the few at my school who make varsity as a flyer, so not to brag or anything but I’m a good asset to our squad. How can I get a perfect heel stretch and scorpion in three or four weeks? And how can I improve my balance? I can do a right scorpion in the pool, but not on steady ground.

Also, are there any stretches I can do to improve my splits? I’m about three inches off the ground in my side splits, and about a foot off the ground in my center split. I’ve been working on them for weeks and I can’t get any better. Any tips?

Thanks :)