This livery is on Boeing 737-800 in the real world. Since there's no Boeing 737-800 in MFS currently, I painted it on default A320neo.
Unzip .zip file into offical A320neo folder.
Find "ADD INTO cfg and json.txt".
Copy fltsim information into Aircraft.cfg.
Change [fltsim.X] into [fltsim.(last fltsim number+1)]
Copy layout information into layout.json.
Remember to make sure format of .json file is correct.
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Also available on sinofsx.