redirecting old blog to new blog using .htaccess

hi,
i am having 2 blog sites on apache server
https://blog.site1.com
&
https://blog.site2.com

Now , i have merged the two blogs to craeeta new blog
https://blog.latestsite.com

I want my user to be redirected to this new blog when they visit any of the 2 older blogs.

So, how can i do that redirect in .htaccess file on Apache server

Please let me know ASAP
thanks in advance
gbhatnagar ??