Unless you're a team leader or an admin, you can't manage your own skills. Talk with your team leader and she/he will do it for you.
Anyway, you can assign whatever learning path you want to yourself even if you don't have that skill. This path will appear in the ‘Others’ column.
Do you think that editing your own skills could be an awesome feature? Let us know!
If you are an admin
If you are an admin, to add a new skill to your profile just go to 'my paths', and click on the button 'add new skill'. Remember that there is a limit of six skills per user.
To delete a skill, just click on the delete button (the bin icon). Remember that you can't remove a skill with active learning paths. Finish them frist, or move the paths to the 'other' column.