Should be fine to exchange iso for shaving point. No need to alter MCB, But things must be done safely, also does rcd protection exist on this circuit. Terminals can normally only contain 4.00mm maximum cable size, so you will need to make a suitable joint to accommodate this.
Thanks for the help, no RCD. I didn't get around to it today in the end and have an electrician coming later this week to look at other stuff, so will ask them to take a quick look. seems that I may need someone certificated to do it anyway, even if I did figure it out!
Thanks KS for the replies. I'd hoped to get to it over the weekend, but other jobs took longer, so didn't! But have an electrician coming on Thursday, and looking at Plan P it seems that I might not be allowed to do it anyway, so will ask them to take a look.
DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!