It's not terribly difficult, but here's a competency quiz for you:
1. What's the Earth wire for?
2. Things often appear to work if you get Live and Neutral around the wrong way. Why is this the case? Why should they never be swapped?
3. In a perfectly installed system and power on, what would be the effect of a person touching each of the three lines while sitting in a bath full of water?
If you can't answer all three of those confidently, then
get a sparky to install it for you. Feel free to PM me the answers if you want confirmation (Disclaimer: I'm not a licensed electrician

). Lots of people will be able to say, "I know nothing about electricity, installed it myself, and I'm still alive!" Consider this: there are people that will say, "I drink drive, and still haven't had an accident". Are you going to go out and drink drive based on that endorsement?
People really do die doing their own 240v work. Not
everyone dies, but it's really not worth the risk.
Edit: slightly changed q2