My question regard the calculation of grade point average in case of an F grade. Are the units or credit hours of the course with F grade included in the calculation of the grade point average. Now when the F grade is removed by retaking the course (asume B grade was earned in the repetition) what grade would be assigned to this course, and would be included in the calculation of the grade point average.

That depends on the program/school you are attending. Most programs will only include the B in the grade point average however the F will remain on you transcripts.

Hope that helps.

How would I request my high school diploma?

My question regard the calculation of grade point average in case of an F grade. are the units or credit hours of the course with F grade included in the calculation of the grade point average. Now when the F grade is removed by retaking the course (asume B grade was earned in the repetition) what grade would be assigned to this course, and would be included in the calculation of the grade point average.
You are going to have to ask your school. I am an admission counselor for a university and it varies from university to university. Some will include the F in you attempted credits and others will remove it when you repeat a couse. This effects how your gpa is calculated. The most common thing I see is the new grade will replace the F in you gpa which will raise your gpa.