Re-did mine as well. Here are a few tips....mostly common sense stuff. Like most, I didn't have the luxury of putting my boat on another trailer while I changed the bunks so I had to carefully measure the bunks for the new wood. Specifically the exact position of the carriage bolts. Once done, I went to the ramp, launched the boat and had the old bunks off and the new ones one within 5 minutes.
1- Do not use pressure treated wood. Find the straightest lumber you can. If there happens to be a slight "wow" in the wood, install the piece convex side up.
2- Bore countersunk holes in the exact locations needed to line up with the metal bunk supports on your trailer. Make the hole tight enough that the bolt doesn't spin.
3- Cut your bunk carpeting to size. Do not cover the underside of the bunk, leave it bare. I used 1" stainless staples with an air gun.
4- If you'll be installing the bunks at a ramp, make sure that you can easily remove the old ones. Bring everything you think you'll need for removing the old bunks and installing the new ones.
It's a cakewalk. Good luck. Any other questions, feel free to PM me.