During my wordpress site i've 10 styles. I have to alter the styles by clicking the hyperlink on the front-end site.(Normally we alter the styles in admin login). I have to alter the styles without login to the admin panel.

Is the fact that possible?..

Install the Theme Switcher wordpress plugin and it'll print a listing of the styles inside your sidebar and customers can click on the links to create the switch. See much more about Theme Switching within the WordPress Codex.