What are the most difficult ways to immigrate to Mars?

In theory, it is feasible to immigrate to Mars, but with the current technology, it is quite difficult.

For example, people go up, but they need suitable supporting facilities, the source of food, and the adjustment of the environment, climate and temperature of Mars.

There are also some factors, such as temperature and humidity, which have to be manually controlled after plants and animals move to Mars, so that the creatures on the earth can adapt, and the corresponding food chain is needed to ensure that they can live normally, and there are methods to deal with corpses.

Although it is difficult, as long as people pursue it unremittingly and make scientific progress, this theory will eventually come true.