Wordpress site Domain name change Impact on SEO

Hi Guys,
I have this wordpress site, whose some of the posts are ranked in top ten for few keywords which are the only source of organic traffic to my site. Now i need to change the domain name from oldname.co to newname.com
While seraching for least impact on SEO for domain name change i came across Matt Cutts 301 redirection video:

https://support.google.com/webmasters/answer/83106?hl=en

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where he emphasizes to create a 301 for each page and post. Now my question is should i create a new wordpress site and add 301 redirects in the .htaccess file of old site? or should i just simply change the domain name in the existing old site? What would be the best option in your opinion to change the domain anme without effecting the ranked posts?
Thanks

i will suggest to change domain name in your wordpress site. then go to your domain registrar and 301 old domain to new.

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prab1996 said:

i will suggest to change domain name in your wordpress site. then go to your domain registrar and 301 old domain to new.

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Second that. I think you can also notify a change of domain in webmaster tools itself.

JournoNick is right, you can change your domain name in Google Webmasters. Be careful on changing the domain name and don't rush!

Found a great article about it, but can't post links yet. Just google for "how to change domain name without losing seo" and hit the second one

1. If you are keeping the url of the content pages ex. olddoma.co/content-page to newdomain.com/content-page

Then you will be just fine doing a 301 domain redirection

2. If you are changing the url of the content page sex. olddomain.co/content-page to newdomain.com/better-url-for-content-page

Then you will need to add a rule for each content page.

Thanks guys,
I followed this step by step guide on "How to Properly Move WordPress to a New Domain Without Losing SEO" by Syed Balkhi the whole thing went smooth and i added a 301 redirect on my old site. Google has already started crawling my new site, so i'm hoping it wont impact the SEO.

I think you should transfer old domain's search engine rank to the new domain and also you should redirect traffic of old domain to new domain, It is a simple task, you just need to transfer some codes that's it!