I don't know if point point by point is the best approach as many of those points (in the second link) relate to not having HTTPS support on the site. I would start by speaking to your Web Host about points raised and securing the site supporting HTTPS.
Also look at Hardening Improvements mentioned in the first link, all of those points have links to help with this.
It is a very long time since I did any web site development and that predates many of the issues reported.