I also recommend the Shure force gauge, works great. You can also read a bit more into alignment here:
A Beginner's Guide to Cartridge Setup
and here:
Set Up a Turntable - Wired How-To Wiki
In my experience you only need the Shure gauge and a protractor for setup. Now, why do you believe they do need replacement? the lead probably don't, unless they are in really bad shape. Try using a magnifying glass (10x or better) to check the state of the needle, if you have none available a decent digital camera with macro would help you a bit though the magnifying lens is way better in my experience.