Below you'll find the address...
Dr. Wahab's Medical Centre,
Road # 12, House # 3,
Telephone: (+880-2) 882 1454,
(+880-2) 882 7553.
So far I know, you don't need any appointment, better you phone call them. But I guess it is better to go in the morning (11 AM) to avoid any Que.
About fees, it would be Taka 3000/each person; better you make a phone call for any revised fees.
Regarding documents to carry, You must carry the passports of all applicant. And not sure about any forms to carry, again, call them and they will let you know.