It's easy, you just have to take your time with it. I actually like doing it.
Find a big pic of the finished product, print it, and keep it next to you when you lace the new rim so you can easily get the pattern right. Or take a pic of your existing wheel if you haven't taken it apart, yet. The spoke pattern will be the same.
If you're not going to use the existing spokes, use a bolt cuter and cut them off. That will save you the 30 minutes.
Take your new spokes and separate them into two piles to make things easier for ya. There will be two different types (based on the bends in them). Some go from the inside of the hub, some from the outside. It should be obvious if you're using the right one when you stick it through and line it up with the rim hole.
Now start putting the spokes on, finger tightening the nipples a few turns on each spoke. Get them all into the rim, verify that your pattern is correct, finger tighten all of them equally.
Put it on the truing stand, true it up. Google it, maybe watch some videos on YouTube. Doesn't matter if you're reading about bicycles or motorcycles, it's the same process. Bike nerds are usually more nerdy about it.
You'll need a spoke wrench and a truing stand. If you have basic fabrication skills you can make the latter yourself.
Enjoy.