IE9 Uninstalling is done via Windows Update control panel. Select the view installed updates and then uninstall IE9 via the context menu.
If you want to uninstall IE9 just because of degraded performance when viewing websites, you can try to turn off GPU rendering which might workaround the performance issue.
- In Internet Options, select the Advanced tab,
- Under Accelerated graphics, check the Use software rendering instead of GPU rendering checkbox.
- Click Apply then OK.
- Restart IE9