Installing new kitchen waste strainer

[Colindr]

Hi I need to fit a new kitchen waste strainer and connect to waste pipe. I need something like this

The old one had come loose from the bottom of the sink hole, and although it had a washer I was confused how it fitted to the bottom of the sink, as it didn't go through the sink hole and there was no wing nut securing it. A screw had corroded away and fallen out of the strainer maybe that was all it needed?

Does anyone have a step-by-step guide to fitting all this, as I've also heard you need plumbers putty to seat the top of the plate-plug and also to fit the underside connector? I want to get it right so I can start using the sink again

 

[seco services]

If the screw had corroded then thats why the bottom part came loose.
The screw go's through the centre of the top part of the waste and screws into a brass insert in the centre of the black bottom part, that's why you can't see it it's internal.

 

[Colindr]

Thanks seco services

I have managed to fit a new one now, and touch wood no leaking. In the end I had to use plumbers mate to seat the strainer that sits on the inside of the sink only. It was a tight fit underneath so couldn't really put any plumbers mate here. I'm hoping the flange and washer will suffice to give a good enough seal. I've tightened the screw as far as it will go and filled the sink twice and can't see any leaks evident. There was a middle piece I had to leave out because there wasn't sufficient room, and connect the P-trap directly to the part that sits directly under the sink.