A couple of people have struggled to change their forum password, so I thought I would quickly write a procedure to do this.
After you have registered and received your temporary email, log in to the forum and then you will see a screen like the one below with your username shown in the top right hand corner; username is Test in this example.

Now you click on your Username and you will be taken to your Profile page shown below.

Now click on the Edit link in the bottom left corner and you will be able to edit any of your profile settings and enter a new password.