How to edit sitecore-XP0.json file

Question

I am trying to edit sitecore-XP0.json file and provide some values in it. But I am unable to find any information on how to edit the file.

I have edited the file like this but it does not seem to take effect. Notice how I added another row as "Value". Can someone please tell me how to edit this file?

"Parameters": {
        "Package": {
            "Type": "string",
            "Description": "The path to the Web Deploy package to deploy.",
            "Value": "C:\\sitecore\\install\\Sitecore9.0.0 rev.171002__single.scwdp.zip"
        },
        "LicenseFile": {
            "Type": "string",
            "Description": "The path to the Sitecore license file.",
            "Value": "C:\\sitecore\\install\\license.xml"
        },
        "SqlDbPrefix": {
            "Type": "string",
            "Description": "The prefix used for all Sql databases.",
            "Value": "sc9"
        },
        "SolrCorePrefix": {
            "Type": "string",
            "Description": "The prefix used for all Solr cores.",
            "Value": "SOLR6"
        },      
        "XConnectCert": {
            "Type": "string",
            "Description": "The certificate to use for encryption. Provide the name or the thumbprint."
        },
        "SiteName": {
            "Type": "string",
            "DefaultValue": "sitecore9",
            "Description": "The name of the site to be deployed."
        },

Answer 1

You really shouldn't edit those files. If you need to override any of the default values, provide those overrides in your installation script:

$SqlMarketingAutomationPassword = "Sup3rSecureS1tecore_pass!" 

$xconnectParams = @{
    Path = "$PSScriptRoot\xconnect-xp0.json"
    Package = "$PSScriptRoot\Sitecore 9.0.1 rev. 171219 (OnPrem)_xp0xconnect.scwdp.zip"
    LicenseFile = "$PSScriptRoot\license.xml"
    SiteName = $XConnectCollectionService
    XConnectCert = $certParams.CertificateName
    SqlDbPrefix = $prefix
    SqlServer = $SqlServer
    SqlAdminUser = $SqlAdminUser
    SqlAdminPassword = $SqlAdminPassword
    SolrCorePrefix = $prefix
    SolrURL = $SolrUrl
    SqlMarketingAutomationPassword = $SqlMarketingAutomationPassword
}