Change cPanel theme from rvskin to x3

There is a known bug that when you change your theme to rvskin you will have a lot of trouble changing back as there is no GUI option to change back.

A few months ago I get a cpanel on another hosting company.  I want to see how it looks rvskin themes, so I switch to it. After that surprise, I can’t check my awstats traffic, so my first idea is to switch back, however this was impossible ...