Unfortunately the login page is embedded and it is not accessible in the administration at the moment. You cannot export it and map it to an external page either. You can only change it via CSS.
You can only hide the footer or use a background image to change the text in it like shown below.
.sfLogin .sfFooter .sfCopy
background: transparent url() no-repeat 0 0;
.sfLogin .sfFooter .sfSupportLinks
This issue has already been logged in our bug tracking system under №107315 but I cannot specify a timeframe when it will be fixed.
Let us know if you need further help.
the Telerik team