Sometimes, when you switch templates, you will find the old template used "Locked" widgets that can't be moved and these widgets get stuck in places you don't want them.
An unlocked widget will have four dots on the left side of the widget box. A locked widget will not have these. In the image below, the menu widget is locked. The top social icons and search are unlocked:
This tutorial walks you through unlocking and moving those widgets.
1. Log into your Blogger account by going to blogger.com and sign in.
2. Once you are logged in from your Blogger Dashboard select a Blog and go to Theme >> Edit HTML.
3. At the top of the screen you will see a Jump to Widget pull down menu next to the orange save template button.
4. Pull down the menu and select the widget that you wish to unlock. If you are unsure of the name of the particular widget you are trying to unlock, have a look at your layout screen as below. Sometimes widgets will not be named however they do appear in sequential order, just as on your website. So if you find yourself looking for the HTML 2 widget it is most likely between HTML 1 and HTML 3.
5. Once you select the widget the screen will display the code for the widget you selected which should look something similar to below.
<b:widget id:'Header' locked='true' Title='My Blogger Blog Header' type='Header'>
more code --------------------------
6. To unlock the widget simply replace locked='true' with locked='false'.
* Also you can totally remove the widget by removing all code from <b:widget> to </b:widget> tags.
7. Click the Save theme button to save changes.
8. Now go to the Layout page. Find your widget.
9. You will now be able to drag and drop the widget to a different widget area if you wish to keep it.
10. If you wish to remove the widget altogether, click on the Edit link in the widget box and click the Remove option.