Put it cut fillet side down (skin up) on a plate with some paper towels, then place about 1/2 lb. of weight on top of it ( a skillet perhaps) and just let it set for 20-30 minutes.
Most Tillapi comes from farms in Indonesia, and is NOT flash frozen, but just frozen normally (why there's so much water), and stays frozen until shipped, remains frozen while a container ship that sails across the Pacific until it offloads, probably in L.A. Harbor (largest on the west coast), or Seattle, and then trucked to a distributor until it's ready to go to your local supermarket. Your 1 lb. of tillapia has taken 2-3 times its weight in fuel and about six weeks to reach your table.
"Food is our common ground, a universal experience." - James Beard