How to install CHAINS MATRIX Builds on Kodi 19 Matrix
Kodi 19 Matrix download.
HOME Screen > Add-ons > Settings button  > Add-ons > Enable Unknown Sources.
BACK to HOME screen > Settings button  > File Manager  > Add Source.
Enter in the top box
Enter Chains in the bottom box > Click OK.
BACK to HOME screen > Add-Ons > Add-on Browser 
Install from zip file > (Click YES to the warning) Chains >
Wait for Add-on enabled notification.
Install from repository > Chains Repository
Program add-ons > Chains Matrix Wizard > Install.
Wait for Add-on enabled notification.
Chains Matrix Wizard is now installed and ready to use.
BACK to HOME screen > Add-ons > Program Add-ons > Chains Matrix Wizard
Select Your build > Install (Fresh install).
Your CHAINS MATRIX build will now download and install.
Wait for download > Force close > Power off if required.
On reboot - WAIT! It can take 5 mins to fully update. Go grab a beer.
Congratulations, your CHAINS MATRIX Build is now installed and ready to use.