How to show blogger widget in scroll box

Login to your Blogger account

Find the Widget ID. See How to find blogger widget ID and Section ID

Go back to Dashboard > Design > Edit Html
(Don't forget to take Backup before you make any change)

Now Check the "Expand Widget Templates" on top right of the HTML window

Find the below code in your template (To find the code you may use Ctrl+F) :

 ]]></b:skin>

Add the below code before ]]></b:skin> the line

/* Scroll box by emdadblog START */
#YourWidgetId .widget-content {
height: 200px;
overflow: auto;
}
/* Scroll box by emdadblog END */

Where to change :

YourWidgetId = put your own blogger widget id

Height: 200px = change height according to your wish

Save and enjoy

Blogger widget in scroll box mission accomplish