Answer:
Being "kicked out" of the Catholic Church is impossible. Once you are baptized you become Catholic and one of the affects of baptism is to place a eternal mark on the soul that forever identifies that soul as a member of Christ's Church, whether in heaven or hell. You can, however, become a "dead member" of the Church. To become a dead member is fairly simple, you can sin and remain unrepentant, thereby depriving yourself of the sacraments by joining another religion or practicing nothing at all, or you can commit an act that will incur excommunication, in which case, the Church Itself will no longer make the sacraments available to you.
The Church, due to spiritual, political or disciplinary circumstances, can pronounce a sentence of excommunication on someone that has shown severe disregard for God, His laws, His Church or Its members. There are certain sins or transgressions considered so heinous, however, that the sinner can incur an automatic excommunication, without the Church having to review and declare it. An automatic excommunication is attached to those sins that are so heinous the soul must have premeditated the deed and maliciously decided to go through with it despite the blatant obviousness of its evil. Automatic excommunication is incurred by heresy, schism (usurping legitimate Church authority), apostasy (denouncing the Faith by a member of the Faith), desecration of the Blessed Sacrament, violence against the person of the pope, involvement in an abortion, ordaining bishops without a papal mandate, absolution of a illicit sexual partner (for priests only, trying to cover their tracks), breaking the seal of confession or being a participant in any of the above. Someone who incurs an automatic excommunication must reveal their sin to a confessor who may require them to confess to a bishop, as some sins are so serious they must be put to a bishop first.
The Church may pronounce an excommunication on someone who is a hardened public sinner or who perpetuates scandal. Frequently, in history, to quell rebellious , warmongering or greedy kings or rulers the Church has excommunicated them - this was a severe and effective move as an excommunicated Christian king automatically lost his mandate to rule a Christian nation, therefore his subjects could ignore him with impunity. Kings were usually quick to curb their behavior and have the excommunication lifted lest they lose their throne completely.