Screening Process was like this.
First You have to be recommended by your Home school to your favorable university. Then you will be screened by your faborable university. It seems that practcially once you are recommeneded by your school, it is yours.
The hardest part is that it is not easy to get recommended, because there is a point system and you have to clear the border and also it is competitive among students above the border especially if you would like to go to a popular university.
Point system is here.This is what we really did.
Now you apply to the assigned (hopefully favorable one, but not necessary due to competitiveness) university. This is also done on the system. You will write a motivation letter with the reason why you chose the university. They ask your need of accomodation at the host university.
Also you will make a study contract; what subjects you will take at the host university.
Note that
You signed on the study contract and your erasmus office do the same too.
You have to wait for a month or so. Then you will be noticed with the result of admission. YES! you can visit the host university! for one semester.