Spouse Visa Renewal

It's almost time for me to renewal my resident card and I was wondering how should I proceed.

When I came first time I arrived with a Tourist Visa and applied for Change of Status to Spouse of a National Japanese, that got approved and let me get my Resident Card.

Now I would like to extend my period of stay. I looked up at the Immigration site but if possible I would like if someone could explain it in a simple way.

I appreciate any comment and advise on the matter.
Thank you.

Info by Immigration on Application for Extension of Period of Stay
http://www.immi-moj.go.jp/english/tetuduki/kanri/shyorui/03.html

Check out the list of documents posted by AK.
https://www.japan-guide.com/forum/quereadisplay.html?0+161418

Get all the documents ready(valid within 3 months after issue), fill in the extension application form,
go to your nearest friendly immigration office to submit.
If they accept your renewal application, you'll get a stamp 'APPLICATION' on your passport/zairyu card. Then you just wait for the result postcard (1-3 months or more recently).
Immigration may ask you for additional documents.

Thank you very much!