TP-Link TD-W8980 - Help needed to wire up and configure.

[#1]

I've just bought the aforementioned device as a replacement for the not-fit-for-purpose £5.99 Plusnet router.
Unfortunately, it is unclear how I wire it up, in particular whether the supplied splitter is used to connect the adsl phone line socket directly to the Open Reach modem (therefore not using the top socket in the new OR faceplate) and, if so, how is the modem then connected to the router.
At least with the original Plusnet device the instructions were clear.
I realise it may be obvious to experienced IT people, but I'm not one of them and have already wasted three hours trying to fathom it all out.
Once the connections have been taken care of, I can then - fingers crossed - try to sort out the software aspect of the installation.
Help would be gratefully received.
Cheers,
Steve

[#2]

Ignore me sorry got the wrong router.

[#3]

Looking at the back of it, half way down this page, you use it just like the Plusnet one.
What you have is an ADSL2+ router with a WAN port, not a VDSL2 router. So you still need the Openreach modem connected to the top socket as now, then modem LAN 1 connected to the WAN/LAN4 socket on the W8980 with an Ethernet cable.
Edit - I remember a few days ago someone has a phone/DSL filter socket with the  top and bottom sockets swapped. The modem goes into the same as it did before, whichever that is. The splitter and ADSL cable you got with the new one are for ADSL when there is no filter fitted to the phone socket and you aren't using a separate modem.

[#4]

Thanks for that...much appreciated.
Am I correct in thinking then that the adsl port on the TP router is left "empty" - in other words the only connection between the router and OR modem is the Ethernet cable linking Lan 1 (modem) and 1 Wan/Lan (router)?
Cheers.

[#5]

OK for a fibre connection, you leave the asdl port unconnected and plug the cable from the OR modem into the LAN/WAN port, they set up for pppoe.

[#6]

Yes.