You can install a plugin to remove those suffix dots but is it really necessary? It is just a matter of copy and paste of one of the following codes in your "functions.php" file that is located in the folder of your WordPress theme. Let's get started:

Method 1. If you want to complete remove the suffix dot add the following code to functions.php

function trim_excerpt($text)
{
return rtrim($text,'[...]');
}
add_filter('get_the_excerpt', 'trim_excerpt');

Method 2. If you want to change the [...] with this ... add the following code to your functions.php

function trim_excerpt($text)
{
return str_replace(' [...]', '...', $text);
}
add_filter('get_the_excerpt', 'trim_excerpt');

Method 3. If you want to change the suffix dot with a "read more" link, than add this code to your functions.php file:

function trim_excerpt($text)
{
return str_replace(' [...]', '<a href=" . get_permalink() . ">' . ' read more...</a>', $text);
}
add_filter('get_the_excerpt', 'trim_excerpt');

That's about it... you really don't need a plugin for this.