Question About Compositing Using Icarus

Hi, I’m having a little, make that a lot of trouble. I can’t seem to be able to wrap my brain around how to do an effect i would like to do for a short video. The clip shows my friend riding his bike into a lake. The thing is i want to remove the lake and make it appear as though he is falling into a lake of Jello. I have downloaded Icarus and have played around with the clip and some of the features, I just don’t know where to begin the process of compiling. I have Adobe Premiere Pro 2 and Adobe Photoshop CS2. Below is a link to a clip from the video.