Content migration from one template to another in Sitecore

I want to transfer content of items that belong to one template into another template.

For example, I have 5 fields in first template:

Tags
Image
Download link
Title
Date

and 5 fields in another template:

Type
Picture
Download Text
Title
Date

Here first two fields are different in the both the templates and remaining 3 fields are same.

So I want to migrate content of items that belong to first template to the second template. Also, I would like to highlight second template is a newly created template and currently no item from that template is created. So ultimately I am modifying the template of 100 items.

I tried overriding change template method of sitecore TemplateManager.ChangeTemplate(Item item, TemplateChangeList changes) but it empties the fields rather I want to retain the field data.

If anyone has any idea about this, please help.

Solution

I don't think there wouldn't be much difficulty to migrate all contents by changing the template. But, the main issue is that there are a number of page items which have to be changed to another template.

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