To uninstall MSI from your MS Dynamics instance, you’ll need to perform steps in both Marketo and MS Dynamics.
In Marketo, click Admin.
Click Sales Insight.
Click Edit Field Sync.
Select the Disable Sync checkbox and click Save.
Make sure you disable the Global MS Dynamics Sync prior to disabling the field sync.
Click Advanced Settings.
Select Marketo Sales Insight and click the delete icon.
When the Uninstall Solution modal pops up, click OK.
It usually takes about 20 minutes for MS Dynamics solution to fully uninstall. However, if you have a large MS Dynamics instance, it could take a bit longer.
Remember to turn on the Global MS Dynamics sync once you uninstall MSI.