Uninstall PSElements8 before Installing PSE9?

I would think that installing PSE9 over 8 would be no problem. I am not a PSE user, but I have had several apps with newer updates and installed them over my older version w/o any problems. You might want to wait for a PSE user to respond, however, to be certain.

 

You're making this way too hard. MacOS X applications do not interfere with each other. Multiple versions of a software title coexist as happy as clams. If the installer does not delete the older version of the application, then there is no need for the user to do so. If, however, you want to delete an application, then drag it to the Trash. The major exception is Microsoft Office which requires its included uninstaller utility.

 

I agree that you don't need to worry about it and just install PSE9 but given that you're new to macs here's a general piece of uninstall advice:

Get appzapper and instead of just removing a program by dragging it to trash, use appzapper and really get rid of the program. I've been using it for years and have never had a problem.