Just go up to the box at the top and click "Account" and then one of the options is to stop the billing for a "Full Access" account. I don't know if you can delete a free account or why you would need to. You can just go away.
You can probably send them a message to delete your account if you feel you need it deleted.
[u]Guitars:[/u] 2014 PRS Santana, 2013 PRS Paul's, 2009 PRS Hollowbody, 1972 Gibson ES-325, 2012 Fender Strat American Standard, 2012 Yamaha Pacifica, Martin M-36, Martin 000-15M, Seagull S6 Classic[br][u]Amps:[/u] Fender Blues Junior III, Boss Eband JS-10, Line 6 POD 500X, Quilter Microblock 45