Do the shops fit it or do you get a pro in.?

If you're asking the question…get someone in

Generally if you buy the shower you fit it. Or just get a man in.
Are you talking Electric, thermostatic or a swap?

Can be either quite easy or a job for a pro only.
All depends on what you've got now and what you want to have. Details please.

Got nothing in at the mo. Just a bare bathroom.

get a pro in, it saves the heart ache

The plumbing side is common sense but electric showers need the sort of electric hook up that takes you in to the can kill you territory. Add water to the equation and it's a no brainier you need a pro.

If you have a combination boiler, then just buy a thermostatic, connect the cold to the cold and the hot to the hot pipes in your bathroom, couldnt be easier.

replacing existing electric shower = easy job do it yourself.

installing new electric shower = job for the pros

They come with instructions – not difficult to install – it's the tiling, running pipes to them that takes the time – the actual installation bit is really easy – all push fit fittings now, so swapping an electric shower over is a 5min job (did one the other night when the solenoid died in my power shower).

you will need an r.c.d and a new 40amp circuit (for 8 kw shower) to your consumer unit, plus a seperate earth bonding circuit to the unit, probably better than already connected to your sink, ie 5mm (i think), plus on/off switch outside bathroom or a string switch to the ceiling which cannot be reached from the shower.

The electrics legally need to be done by a electrician if you need to install any of the above rather than replace.

Then a mains water feed not from a tank, useful to have a on/off connector so you can replace unit with out turning mains off.