I managed to fix the breadcrumps and its module position.
I put the login module in its place.
It is covered by the logo and menu area.
I guess I have to make the images smaller, but I don't know if this will be enough to show the login and logout in the breadcrumps position.
This is the corresponding html-code:
<div class="breadcrumb">
<div class="module__rmlogin">
<div class="module">
<div class="module_padding">
<div class="module_content">
<table style="margin-left: auto; margin-right: auto; width: 320px; height: 80px;">
<tbody>
<tr>
<td class="wglogin" style="text-align: center;">
<h3 25px;="" padding-top:="" style="text-align: center;">
<img width="128" height="60" alt="WGloginbg" src="/templates/j51_arkadia/images/WGloginbg.png">
</h3>
</td>
<td class="log_out_a" style="text-align: center;">
<span style="font-size: 12pt;"> </span>
</td>
<td style="text-align: center;">
<form method="post" action="#">
<input type="hidden" readonly="readonly" value="http://eu.wargaming.net/id/" name="openid_identifier">
<button>
<img width="75" height="25" alt="WGbutton" src="/templates/j51_arkadia/images/WGbutton.jpg">
</button>
</form>
</td>
</tr>
</tbody>
</table>
</div>
</div>
</div>
</div>
</div>