For the brake fluid part, may I suggest a search under " brake fluid flush ".
On the sparkplug issue:
1. If you are getting Bosch F7KTCR, there is no " adjusting" to do.
2. I normally like to change plugs on an aluminum head engine when it's cold.
3. Apply a VERY small amount of anti-seize compound on the plug threads before installing them.
4. Use a little dab of dielectric grease on the plug boots, before you re-connect them.
P.S. Welcome to the forum.