So, you've read all about using Less and are keen to start using it in some of your older projects. You've started working with it on your newer sites and love how it makes writing CSS so much more manageable...but, you're probably thinking: how can I incorporate it into an older site?
Well, you're in the right place—making the change in older sites doesn't need to be difficult, as long as you keep these tips in mind:
Make sure you have installed Firebug with Less support, as outlined in Chapter 2, Building a Less Development Toolkit. Trust me on this; it will make debugging your efforts so much easier!
Run your existing CSS through a site, such as W3C CSS Validator (http://jigsaw.w3.org/css-validator/validator). If you haven't already done so, this will help spot any errors and ensure that your code validates properly, before beginning to convert it to Less.
Try to get into the mentality that converting Less should be done in blocks at a time and should be an...