My Mum did this.
She wrote to the Hospital University for the paperwork.
Completed it and sent it back to them.
They keep it on file until the dreaded day comes for the family. The Senior Lecturer examines the body to ensure it is acceptable for the University.
They then remove the body.. and normally they write to ask if you wish the body to be returned to the family, or arrangements to be made by them.
I chose the latter.. but did attend a beautiful memorial service at the University 18 months later. Families of the deceased all attended the service, as well as the Students. A token wreath is placed in the chapel on behalf of the students and Lecturers. Deceased names are written in the book of remembrance. xx