[Plugin: SimpleModal Contact Form (SMCF)] How to not lose style changes when plugin is updated?

The question is in the title. The answer in the FAQ on how to change the style of the contact form is not a very good one being that it is temporary…or we have to remember to save our changes when the plugin gets updated.

How to not lose style changes when plugin is updated?

http://wordpress.org/extend/plugins/simplemodal-contact-form-smcf/