BlastingKap

Just wanted to leave a thanks here for the guide. Picked up an i7 8700 and it's been fun getting it to work in a z170 maximus hero.
 
One thing i wish i'd realized sooner is that the stock voltages for the non-k parts are waaaay too low. I've essentially had to 'OC' the 8700 up to stock speeds by adjusting voltages and power manually. SVID and Auto anything was a complete mess and it couldn't even reach the Windows login screen.
 
Methods/Tools used:
- kapton tape for the two isolated pins
- a very small strip of conductive tape for the SKTOCC pins
- a CH341A to flash the bios
- a cheap chip puller (almost destroyed the legs on the poor DIP chip without it)
- stock BIOS v2202 (as it came highly recommended)
- the russian coffeetime tool (v0.85) - picked the experimental 'inject all' option for Asus.
 
Lessons learned:
- The CoffeeTime tool ships with the 64-bit version of cecho. I ran the tool in an old Win7-32bit VM and had to replace it with the 32-bit version.
- The AIO Tool from Win-raid has no config menu. It also needs to be executed close to root folder - I ran into a bunch of MMTool crashes due to path length exceeding the maximum. Even when it worked I was stuck on POST code 31 with a skylake CPU installed. It's possible the AIO tool doesn't keep skylake support?
- CH341A windows software sucks. If you can run it on linux do that. I had problems flashing (read/verify would fail) until I tried  v1.31 'Free' version. 
- All of these tools trigger virus scanners and unpacking them will get a bunch of their files quarantined/nuked instantly. Likely false positives but if you like to be cautious just use a VM or a PC that's isolated from the net.
- If you care about your boar'd SN and MAC address, make a backup of your OG BIOS with the programmer before you start!
- Even after dialing up the vcore to 1.4v, couldn't obtain an all-core sync higher than 3.5GHz. Turns out the Auto CPU Core Cache Ratio is also garbage and I had to dial in 34 min and max. I could then drop the vcore down to 1.3v and achieve a stable system (Prime95 - Blend - 30mins). Cache Ratio of 36 or higher wasn't stable without putting in more vcore than i was comfy with running 24/7.

4. BIOS Modification
5. Flashing the Modified BIOS
6. First Start
7. Troubleshooting, Bugs, and Features

Hello guys.
I used a search engine and found that the possibility to run CoffeeLake processors on Sky\KabyLake motherboards was brought up here before, but did not receive a wide coverage, even though there are many people who have good Z170/270 motherboards and want to upgrade their obsolete 4C/8T i3s i7s.
Many such cases.
 
The modification itself is more than a year old, but it's better late, than never?
To those who are interested, I present the translation of this guide below. Thanks to all the people who made this modification possible and to the all people who contributed to this guide. I am not a native speaker, so corrections are welcome.
 
 
0. Before You Begin. Disclaimer
You are responsible for your actions and consequences thereof. There is no guarantee that everything will work as it should or work at all.
1. Highlights
2. BIOS Dump and Personal Data Extraction
3. CPU Preparation