Our Mira shower, not electric, is leaking so sent for a service kit. I have watched the Youtube video a few times to see how to do it. Why does it always look easy in these videos? I am unable to get the 55mm brass nut off using a pipe wrench to access the parts that need sorting. Tried the boiling water, (4 kettlefuls), hammer bashing round the nut and a good dollop of penetrating fluid. All to no avail. Then again it is 29 yrs old. Any ideas on next possible solution please?