open includes/templates/YOUR_TEMPLATE/css/stylesheet.css

scroll to the bottom of the page and add the following
.testimonial {
color: #000;
padding: 0 5px 5px 5px;
text-align:left;
}
.testimonial p {
margin: 0; padding: 5px 0;
}
.testimonial span {
float:right;
}
.testimonialImage {
margin: 0;
padding: 0;
text-align: center;
}

the other section is used to add meta tags when vewing your testimonial pages and is not included in the stylesheet.

There are instruction earlier in this support thread on add the meta tag section (I just don't remember where exactly)