Droste - I say again -
NO ORAL EXAM for BGI, AGI or IGI. Just written exams.
These exams are not necessarily easy, by the way.
And read again which exams you need.
Would suggest you do the following exams to have ALL ground instructor privileges -
You can teach PPL, CPL, IR and ATPL
1. Fundamentals of Instruction
2. Basic Ground Instructor, and
3. Instrument Ground Instructor
Or, to have teaching privileges, but for PPL and CPL only -
1. Fundamentals of Instruction
2. Advanced Ground Instructor
No expiration date on Ground Instructor Certificates.
Happy contrails