https://rog.asus.com/forum/showthread.php?76993-Guide-How-to-install-windows-8-8-1-10-The-proper-way...
Be sure to make an SSD image complete image on external USB disk thumb drive. you'll need this in the future
Be sure before you do anything to back up you eSupport Folder it hold all your Orignal drivers and software some that you won't find anywhere else to download
Download your manual and any updated BIOS, Chipset Drivers, Etc from Asus Support downloads
Download and create your install media from Microsoft MCT
Windows 10 clean install tutorial

I highly discourage you from clean installing unless you have screwed up your notebook so badly that it is your only choice. There is not one thing to gain by clean install windows on the current notebooks. Any Asus software you don't want can simply be uninstalled.
If you're having window issue they are usually easily repaired using DSIM tool. These are not the days of XP and Windows 7 where frequent clean install was required. Window 10 is quite stable and easily repaired when we screw up or MS updates Screw up.
You should always have the latest hardware drivers handy after any Windows update and MS thinks there native driver is what we need when in fact they cause all kinds of issues for us. it's best to block all driver updates and just keep up with them and install manually when new ones become available.
To protect your self you should download Macrium Reflect Free and create frequent images of your C:\ SSD or drive. Trust me they will save your butt many times.

The other issues that have come up with the April upgrade is lack of disk space you need 60 to 80 GB of free space. Also, you should have all your hardware driver up to date before trying to run it.
You should run Disk Cleanup and System clean up this will get rid of some trash temp files clean up your system and give you some extra disk space
On your failing to install the April update you probably need to repair you current windows open a Command prompt in Admin mode and run each of these tool one at a time don't get impatient some will take quite a while to complete repairs. Just copy and Paste

Dism /Online /Cleanup-Image /CheckHealthDism /Online /Cleanup-Image /ScanHealth
Dism /Online /Cleanup-Image /RestoreHealth
Dism /Online /Cleanup-Image /StartComponentCleanup
SFC /scannow
chkdsk C: /f

You should download and create a USB install media from MCT I linked above and attempt a repair install start the setup.exe from within windows and be sure to select to keep all your files and folder this will include all installed programs. Good luck and let us know how it all comes out.