Help with converting a multiniche blog to a single niche

So you are taking over the management of a new blog and on the day you took over you logged into the wordpress dashboard, took a look at the posts published to find out that the last owner has been directionless – actually writing about everything on the face of the earth.

You want to make this blog work and this means you have to convert it to a focused niche to help with SEO and monetizing.

But here is the problem, the former owner has already published more than 300 blog posts on , like I said earlier, almost every topic on the face of the earth.

I checked the analytics and found out that the traffic is miserable; the blog is barely getting up to 40 pageviews a day. So poor for so much content.

So I am requesting for guidance from the gurus in the house. How do I proceed to make this blog work?

I already have a niche in mind but don’t know what to do with the already published posts.

Should I just ignore them and start writing on the niche?

Or should I delete everything and start afresh?

Talking about deleting how do I handle the 404 effect from Google because there is going to be lots of not found pages on the webmaster tools.

Should I ignore the blog and tell the owner to let it expire because it is a failed project?

In this case this is an aged domain of about 4 years and we are worried about letting such age factor that can help ranking later go to waste.

A little help will be appreciated.

Does the website have strong backlinks already? The age of the domain means buck all if you don't have solid links.
The age of the content matters, but if it is irrelevant to your current choice of pursuit, then that is irrelevant, especially without powerful backlinks.

Start there in your decision.

I think the oldest articles are at most 6 months old. There are few quality backlinks to the site and they link to individual contents. So what do you think?