I walk you through the process of making a contribution to Spacemacs, though the process applies to any project that uses git and Github. No command line use is needed, since you already have a Spacemacs checkout, everything is done with Magit in Spacemacs and the Github website. I've got a blog post describing this whole process on my blog: http://iam.travishartwell.net/2015/07/29/how-to-make-a-pr-for-spacemacs/