The release mechanism requires you to pull up, as in towards the sky, to release the engine. Its not like normal pull ropes where you can just pull it to your body. However, it is easy to pull and Im certain you could rig something up to fit your situation. Something like a piece of pvc that you slide over the lever then push up would work. Here is the lever:
http://www.calfishing.com/dc/user_files/4570-Lever.jpg


The good news is that it takes minimal effort to pop the engine out of the cradle once you unlock it. You could just push the head of the engine up and it would pop right out because of the shape of the cradle, its upside down!! Here is a photo:
http://www.calfishing.com/dc/user_files/4571-Cradle.jpg

Trust me, its very easy to pop out, and then pull the engine back into this cradle. I really do like the cradle.

You could rig a rope to the head of the engine to make pulling it into the cradle easier. So seems the only hurdle you may have is reaching the release lever, but I dont see that being much of a hurdle. Also, you can easily control the foot pedal by using your hands.