1. BACKUP YOUR DATABASE
2. Backup all your existing installation YAF files

1. Remove the following directories from your forum root directory:

• _\App_Browsers:
• \Bin
• \Content
• \Controls
• \Dialogs
• \Install
• \languages
• \Pages
• \Resources
• \default.aspx
• \error.aspx
• \Global.aspx
• \UrlRewriter.aspx

1. Unzip the file structure YAF-vX.X.X-Install ZIP archive to the folder you want to run YAF to run inside.

1. Copy the Images and uploads folder to the wwwroot folder

The connection string, mail configuration and membership provider settings need to be migrated from the web.config to the appsettings.json file

1. So the connection string from the web.config

<add name="yafnet" connectionString="data source=localhost;initial catalog=yafnet;Integrated Security=True" providerName="System.Data.SqlClient" />

will be

{
  "ConnectionStrings": {
    "DefaultConnection": "data source=localhost;initial catalog=yafnet;Integrated Security=True;TrustServerCertificate=True;"
  },
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft": "Warning",
      "Microsoft.Hosting.Lifetime": "Information"
    }
  },
  "MailConfiguration": {
    "Mail": "",
    "Password": "",
    "Host": "localhost",
    "Port": 25
  },
  "BoardConfiguration": {
    "GDPRControllerAddress": "",
    "BoardID": 1,
    "CategoryID": 0,
    "ConnectionProviderName": "Microsoft.Data.SqlClient",
    "DatabaseObjectQualifier": "yaf_",
    "DatabaseOwner": "dbo",
    "MultiBoardFolders": false,
    "AllowLoginAndLogoff": true,
    "SqlCommandTimeout": 99999,
    "URLRewritingMode": "Unicode",
    "UseHttpsRedirection": true
  },
  "AllowedHosts": "*"
}

2. the Settings from the mailSettings/Smtp are now under MailConfiguration in the appsettings.json
3. And the appSettings are now under BoardConfiguration

1. When the Application runs after the files are copied to the server, then the Database will be updated automatically.