Need to alter my Pennco Slider to open on other side




You patio door appears to be a Vinyl type door. I'm not 100% sure, but I believe you can actually flip the doors upside-down to convert them to a left or right hand oriented door.
In some cases, the manufacturer would install rollers both at the top and bottom rail of the door for this purpose. It would be a little bit of work, but you might be able to accomplish what you want to do. That said you may want the help of a local professional regardless.
Also take a look at the related videos on vinyl patio doors. These might help you in determining if it can be done. We don't have any drawings or manuals for this door, and I'm not sure if you can get a hold of them, but our information may still be helpful.