what is it exactly that your trying to do. i assume it's not pop your warrenty counter. i also assume your on 4.3. from my own personal experience installing a custom rom kind of requires a custom recovery as you will want to do a backup. i also suggest using an app called samsungtool v 2.0 to backup your efs partition just in case. instructions related to installing a custom rom can be found in any rom thread on here. for the most part it's the same for every rom with exception to a few. but again you do all this on your own. btw this will pop your warrenty counter but if your sure about what your doing and your warrenty is up. might as well pop it.