Flexible Theme

I want to pinch certain features from the Flexible Theme. This is a theme that incorporates accessibility. However I dont want to use the theme as such, just pinch the bits that I need but I dont know where to start. The items that I want to use are as follows:

The ability to change the size of the font by clicking on a button in the header.
The ability to change the colours on the screen again by clicking on a button
To have options in the header, such as 'skip to content' and 'accessibility guide'

Thanks