Anyone familiar with working on compound bows?

My dad had some old bows at the house and I took one from him to turn into a bowfishing bow with the AMS kit. http://www.pickaspotarchery.com/product/AMS-Retriever-Pro-Combo-Kit

However, there are some issues I need addressed. It's an early 90's PSE Pulsar with a draw of 29" and weight from 45-60 lbs.

It for sure needs a new string and new cables, but I was wondering if there was any way to adjust the draw length on it. Because it is so old once it is set for bowfishing it will stay that way. So I would like a draw of about 27" and the weight at 45 or lower if it's possible. Is it adjustable on these old bows or am I doomed to over draw for the life of it?

What is the likely hood of them being able to slap some smoother cams onto it? I can't afford a new bow just for fishing, especially when the chances of me dropping it in the river are pretty high.