there are quite a lot of them available out there depending on the programming language you are using. for example python: https://stackoverflow.com/questions/46350765/convert-json-to-csv-with-python-3
the .csv file can then be opened with excel and you can start doing anything you want with that data.
To be fair, no programming required (although if he's looking to automate this, it would be better). There are hundreds of sites w/ simple scripts to convert JSON to CSVs
For example: https://json-csv.com/
If you do want to automatically create a CSV file, you can do something like the following (in PHP for example):
Idea/some code from: http://thisinterestsme.com/php-convert-json-csv/
$apiUrl = 'https://api.coinmarketcap.com/v1/ticker/';
$apiData = file_get_contents($apiUrl);
//Decode the JSON and convert it into an associative array.
$jsonDecoded = json_decode($apiData, true);
//Give our CSV file a name.
$csvFileName = 'data_export.csv';
//Open file pointer.
$fp = fopen($csvFileName, 'w');
//Loop through the associative array.
foreach($jsonDecoded as $row){
//Write the row to the CSV file.
fputcsv($fp, $row);
}
//Finally, close the file pointer.
fclose($fp);
// Say something.
print "Complete!";
If you run the script, it will create a file named 'data_export.csv' with the JSON to CSV data. It may require a few edits to make it perfect/flawless, but hopefully you get the gist.