When were your friend's dps made special guardians for his ds?
How old is the dc and does he have contact with his dm as well as his df? Has your friend been granted a Residence Order for his ds at any time and does he and/or the dc's dm pay maintenance for his upbringing?
Other than the statutory duty encumbent on the local authority to provide a report to the Court as to the suitability of the applicant(s) and other relevant matters, were Children's Services/social workers involved in your friend's decision to consent to, or not to contest, his dps application to be made special guardian(s) of his ds?
Special guardianship does not remove parental responsibility from the birth parent(s) but, by order of the Court, special guardians are given parental responsibility to the exclusion of all others with parental responsibilty for making both the day to day and all the important decisions for the child, such as which school they attend, until s/he becomes 18.
When the Special Guardianship Order was made did the Court also make a Contact Order in respect of the dc's contact with his df and/or dm and what 'unreasonable demands' are your friend's dps making in respect of his contact with his ds?
If your friend is unable to resolve any disagreement he has with his dps in respect of his ds directly with them, he's best advised to contact National Family Mediation on 0300 400 0636 and arrange an appointment.
If mediation is unsuccessful he can apply to the Court for a Specific Issue Order to determine the issue, or for a Prohibited Steps Order if he is seeking to prevent his dps from doing something he does not wish them to do in relation to his ds.
Your friend cannot apply to end the Special Guardianship Order without having first obtained permission from the Court and, if this is his intention, he should consult a solcitior who specialises in family law.