Migration is only possible from mm_forum 2.0. There is no backwards compatibility to mm_forum 1.x!

• Install typo3_forum
• Execute the Scheduler Task Database Migration
• Open your root TypoScript Template Record and include typo3_forum's static TypoScript
• Change your TypoScript configuration (e.g. in your template extension or Typoscript records) from plugin.tx_mmforum to plugin.tx_typo3forum
• Uninstall mm_forum
• Clean up the database using the Install Tool "compare" functionality.
• If you have custom fluid templates for the forum using the forum's ViewHelpers you have to adjust the namespace declaration accordingly. E.g. {namespace t3f=Mittwald\Typo3Forum\ViewHelpers}