Would a complete layman be able to manage the install of a combi-box?

I would say yes. Granted I AM biased,😉 but it is well within the skills of any DIYer who is comfortable with tech. By far the most tricky part of any install is aiming the dish and you say you have that already. Like any new topic, it's easy to get overwhelmed by the jargon. Although I can't name a step-by-step guide off the top of my head, companies like freetv.ie have some videos directly aimed at the Irish market. On first startup, the box runs a wizard to guide you through the basic setup of your network (if connected) and scanning for channels.

The two main things to consider when switching from an existing Sky install are:-

1. Was it using Sky Q. If it was you may need to swap out the LNB, the thingy on the dish arm. Only some boxes are compatible with Sky Q. Mechanically, it is a straight swap. Just do not move the dish itself.

2 You will need a conventional Saorview aerial. If you are near to your local Saorview mast, you might get away with an internal set top aerial. Outdoor ones are recommend. This will help you decide. https://saorview.ie/en/check-coverage/

Again, like anything else, you can make it as complex as you like beyond that if you have greater needs or ambitions E.G. multi-room and so forth.

I've been running a Zgemma H7S*** as my main box for several years now without issue. They are actually 4K compatible although there isn't anything available in 4K for free right now. You can record multiple shows at once if needed.

*** If you decide to purchase, be sure it is the H7S model. There are other versions that may not be suitable for the Irish market.

A different make, and 5 years old but this YouTube video gives a flavour of the Enigma 2 software. From 19 minutes in the video. The software is called an Image in the jargon, which confused me back in the day. There are different versions, and they are updated often, but they are basically the same.

The installation Wizard gives a step by step for the process. Get the box tuned in first for TV channels and then there is a whole world of other stuff which can be done gradually after that. Look on YouTube for other videos as well, and on Google. And the dedicated Zgemma H7S thread has over 2000 posts.

Probably the need for recording would rule out using the TV on its own. With the aerial and the satellite cable plugged in directly (if it has a satellite tuner compatible with the LNB). But before getting a box you could get familiar with what the TV can offer using the menus on the remote.

Yes, and the instructions in the video are given in written form by CalamariFritti above. You will learn by doing. If it all looks too daunting you could get a box which does not use the Enigma 2 firmware. But it won't have nearly as much possibility for customising your choices. Plenty of videos in this link showing how those type of boxes work.

https://www.freetv.ie/amiko-mini-combo/

Can you tell me the mke and model of your ttv? I have a spare zgemma h7s all set up and ready to go with 4 images on, its like new ie hardly used. its got 128gb ssd.

For Woodcock Hill a Group K UHF aerial is what you need for saorview

https://www.freetv.ie/grey-group-k-uhf-aerial/

The LNB on the dish may be ok as it was used recently enough for Freesat, test it out before doing anything else.

A soarview aerial is just a normal looking aerial, like this.

AFAIK (but not 100% sure) it needs to be pointing in a certain direction which depends on where you live. All the ones in my estate are looking like this and are pointing in the same direction anyway.

But tbh I know my way around software and bits but for that I just got the local 'aerial/dish/telly man' to do it. I wasnt going to climb up on my roof and mess around with that. On the upside he took down a lot of old aerials that were no use to anyone only to the crows. I just have this yoke on a pole next to the chimney now and the old sky dish by the side of the house. A lot tidier. He ran this aerial into the attic and from there it connects to a box that was already there for the old UHF/VHF stuff which then runs more cables into the individual rooms. Def'ny a telly man job IMO. Cant remember what I paid him but I dont think it was all that much - €150 or €200 or so.

Depending on where you live you may get away with something smaller. Like an indoor version or so.

All put together it may sound like a few bob at this point - zgemma box, hard disk, dish/lnb upgrade, saorview aerial - but considering what you save every month over Sky its all money well spent.

I'm not clear what you're saying. Are you saying you do have saorview or had saorview at some point but just not sure where its coming from?

Unless you need to run another cable it doesnt really matter where it is as long as it works.