The remoteness and ruggedness of Pitcairn's geography, the insularity of its bureaucracy, and the scarcity of its resources conspire to make it a very difficult place to visit.
Visitors staying on the island for any length of time require a license from the governor, because the irregularity of transport means they're effectively residents of the island for the next several weeks or even months. These licenses require proof of good health, the means to leave at the end of the visit e.g., passage on an upcoming ship, at least NZ$300/week to cover your cost of living on Pitcairn, various other conditions, and a $100 fee; they are valid for six months. mailto:email@example.com
There is no airstrip in the islands, and it's out of range of land-launched helicopters, so flying is not an option. The largest flat area on Pitcairn would offer a very short runway, and level Henderson Island is both a UNESCO-listed bird sanctuary and inconveniently located. The nearest airport is on Mangareva in the Gambier Islands, 330 miles away. You can catch a charter vessel from Mangareva.