Well... it would seem, that css is what u need... just style the buttons, instead of transforming the html into "something else".
So the steps to use css is these:
1) In your html, place the output of WebLoginPE in a div with a class of "WhateverYouLike".
2) then setup the css like this:
/*General attributes for all the buttons*/
.WhateverYouLike button {
width:50px;font-size:9px;line-height:9px;text-align:center;overflow:hidden;
margin:0; padding:0; border:1px solid #000;
background:url(img/ButtonImage1.png) transparent no-repeat scroll 0px 0px;
}
/*Now: change the background-image for any individual button via it's id selector*/
.WhateverYouLike #wlpeLoginButton { background-image:url(img/ButtonImage2.png) }
.WhateverYouLike #wlpeReminderButton { background-image:url(img/ButtonImage3.png }
.WhateverYouLike #wlpeRegisterButton { background-image:url(img/ButtonImage4.png }
.WhateverYouLike #wlpeResetButton { background-image:url(img/ButtonImage5.png }
.WhateverYouLike #wlpeResetCancelButton { background-image:url(img/ButtonImage6.png }
... thats pretty much it... I hope this helps you