From the left hand menu choose 'Members' Area'
You should see the page below.
If you do not see this page:
Once you see the correct page, click the 'Log in' button towards the bottom of the screen.
You should see a log-in dialog box which says something like: 'http://grsmembers.eu is requesting your username and password. The site says: "German Railway Society Members' Area"'.
Remember that the letters and numbers must be entirely correct -- the server cannot help you out. 1, I and l are different characters and so are O, o and 0. If you don't get it right the first or second time you will still probably succeed in the end!
Press OK. If the details are correct you will see the page below. You are now logged in.
If the details are not correct you will see the page below. You can reload the page to display the log-in dialog box again and have another try.