My 300 has the same steps. There is a set screw on the end of the stainless bracket holding the step. Take out the screws thru the step at both ends. Loosen the hex head set screws on both end of the step brackets, then carefully remove them and the insert behind them that clamps to the verticle rail. Then you should have plenty of slack to move one end up or down and slide the wood out of the bracket. The insert may not come out until you have the step almost completely off. The wood step is notched around the verticle rail.
The only reason to make new steps is for a project. The old ones are in very good condition .... just worn. I made new swim deck inserts and they look great.