It’s really simple guys , before changing template search your widgets code without putting check in expand widgets box.
UPDATED:
Select the widget code as shown in the image below. search for: <div id='sidebar'> copy all widget code between <div id='sidebar'> to </div>

Now save the widget codes shown in between yellow box to notepad. Copy and Paste all your widget codes.
After doing this Upload your New Template . After uploading you will get a message like this

At This stage don’t click Confirm & save tab. Rather search for the following code <b:widget id=’ , Now paste the widget codes you have saved immediately above or below the code in yellow
After adding the widget codes save your template.
UPDATED:
Select the widget code as shown in the image below. search for: <div id='sidebar'> copy all widget code between <div id='sidebar'> to </div>
Now save the widget codes shown in between yellow box to notepad. Copy and Paste all your widget codes.
After doing this Upload your New Template . After uploading you will get a message like this
At This stage don’t click Confirm & save tab. Rather search for the following code <b:widget id=’ , Now paste the widget codes you have saved immediately above or below the code in yellow