Conver Putty ppk key to SSH key

In many occasions I needed to convert a Putty ppk private key nack to open ssh key to be able to use it directly from a linux box command line. It is fairly simple to do but I always need to look it up so here it is for easy reference :

Install putty using yum in Fedora.
If you are using Ubuntu you need to install putty-tools as well

From the command line give

then log onto your system using