Elements 10 on El Captan has recently started crashing

Good morning.  I am an artist working in the north of Scotland.  I have been using Photoshop elements 10 for several years.  I have a mini Mac on El Capitan version 10.11.6.  Photoshop is now crashing all the time.  As such I need advice as to how to delete it and install it again and if it then doesn't work I feel I will have to buy a newer version.  I particular, where and how do I find 'the package' to install. I'm nervous about buying a newer version having read on forums about problems and I want to be assured that I can get my money back if the software doesn't work.