1. Install URL Rewrite 2.0 module to your IIS8
2. Open IIS Manager, expand the Sites container and select the website you wish to configure the http redirection.
3. Once highlighted, doubleclick the URL Rewrite option in the right hand pane. Select Add Rule and configure the following:

ADD new

• Select: Blank Rule
• Name: http to https
• Match URL – Requested URL: Matches the Pattern
• Match URL – Using: Regular Expression
• Pattern: (.*)
• CONDITIONS

• Conditions: Add
• Condition Input: {HTTPS}
• Check if input string: Matches the Pattern
• Pattern: ^OFF$
• Click OK
• ACTION

• Action type: Redirect
• Redirect URL: https://{HTTP_HOST}/{R:1}
• Redirect type: See Other (303)
• Click Apply
• Requests to your site via HTTP should now be redirecting to HTTPS.