The following material is from the UK Graduate School Bulletin description of Specialist in Education.

Program applicants must meet the following prerequisites:

Completion of a master's degree,
A 3.4 GPA or higher on all graduate work,
Meet the requirements for a teaching certificate or have credentials appropriate to the field of specialization, and
Have completed at least 30 semester hours in courses in education (graduate and undergraduate). CV
The CV or resume must include prior education/degrees, the institutions attended (including years), prior teaching certification and/or other professional certification/licensure (if any), and employment history.
Personal Statement
Within the personal statement, applicants must include a biographical sketch that addresses the evolution of their professional career, research interests, and their professional goals as they relate to the doctoral program of study. Applicants must also indicate their proposed departmental area of emphasis from among the following: Assistive Technology (AT), Interdisciplinary Early Childhood Special Education (IECE), Learning and Behavior Disorders (LBD), Moderate and Severe Disabilities (MSD), or Rehabilitation Counseling (RC).)
Writing Sample
Applicants must include a sample of professional academic writing such as a Master's thesis, published manuscript, or a major paper from previous graduate study.
GRE
Three letters of recommendation
Recommenders should address the applicant's ability (demonstrated or perceived) to work with students with disabilities.
An inteview will be conducted. For the Graduate School, the minimum acceptable TOEFL score is 550 (paper-based) 213 (computer-based), or 79 (internet-based). The minimum IELTS score is 6.5