Possession is a matter of “fact”. Therefore, the only way to take care of it is through “de facto” (actions), not through “de jure” ones (contracts or agreements).
If someone enters your property, or the property in which you have the right of possession, of course you have legal actions to recover the possession. But it means going to court, which implies cost and time. Because it is a constitutional principle that “no one can take justice into his own hands”. Therefore, you cannot “kick the invader out”. Unless there is an issue of flagrancy, because in that case the issue would be seen in a different light.
But in order to avoid the above complications, the general advice is: take all the necessary precautions to take care of the possession: if it is a piece of land, enclose it; if the extension justifies it, hire a guard. It is very likely that the guard’s salary will be less costly than the expenses and fees of a lawsuit.
