You probably don't want to do this yourself. It's not that it's hard but you need the right tools and a reboot kit. The boots have a metal band that holds them on and needs a special tool to krimp/compress the metal band. You would need to pack the boot with grease too.

The reboot kits cost like $60 I think. I've got a boot leaking on my passenger side and was going to have a buddy at the Honda Dealership fix it but since the kit cost $60 I didn't think it was worth it. You can get a new or rebuilt axle for not much more. I'm holding out for some custom axles since the joint isn't clicking yet.