Hi Dennis & welcome
Rebuilding is fairly simple and you get better at it with experience. Cost savings not withstanding the simple convenience factor alone makes it worthwhile.
A lot of what's written will suggest you need to go out and buy a good ohm meter but I'd disagree with that and happily sell you mine as I don't bother using it anymore. I find it just as simple to pop the atty back onto the mod to measure its resistance than it is to pull out the meter (yes I can be lazy for sure at times). Of course if you are using a mech mod then you definitely need a meter.