Changing the layout colour and icons of the logon page

Hi iam new to the F5 product and iam no way near to being a web developer, but i would like to be able to customise the

 

default logon page for Network Access.

 

Now i have managed to work out that this is comprised of the editing logon page and the webtop, but iam little unsure of what goes where.

 

Is there any one that has experience of this or could point me in the right direction of some relevant resources ?

 

I have tried looking at the configuration guide, and tried to replace the F5 logo with our own logo with the result that the page became missformated.

 

 

Cheers Craig