Where change the max lenght of the username?

Hi
I use HIKA and the component ExtendedReg on my page.
User can register on the page and login only with e-mail adress, so e-mail and PW.
There is no username.

The login form in the HIKA checkout has now 2 e-mail fields. -> see code below
When I look into the HTML code I see, than one of them is (or was) the username, the other is the original e-mail field.

The problem is, than one of the fields has a very short maxlength, that is not enough for e-mails.

How I can resolve it?
Can I change the maxlength somewhere or remove the standard e-mail field?
Where I can do that? So I have to change some PHP files (overrides)?


<tr class="hikashop_registration_username_line">
<td class="key">
<label id="usernamemsg" for="register_username">
E-Mail </label>
</td>
<td>
<input id="register_username" name="data[register][username]" value="" class="inputbox required validate-username" maxlength="25" type="text"> *
</td>
</tr>
<tr class="hikashop_registration_email_line">
<td class="key">
<label id="emailmsg" for="register_email">
E-Mail </label>
</td>
<td>
<input id="register_email" name="data[register]" value="" class="inputbox required validate-email" maxlength="100" type="text"> * </td> </tr>[email]" value="" class="inputbox required validate-email" maxlength="100" type="text"> *
</td>
</tr>