Before uninstalling PSE6 log-in to your Adobe account and check your products to make sure a download is still available. If it is, download the package and then uninstall the program via the control panel. Look for the set-up file after unzipping the download folder, to re-install.
On PSE 10 all the selection tools are in a group of four above the crop tool. It’s possible to right-click on some of them, to reveal all the options nested below each icon.