This video [5:00] gives an overview of the process of having a Needs Assessment.
If you are a home student, you will probably be eligible for Disabled Student's Allowance (DSA). To access DSA funding, you will need to have a Needs Assessment. For an overview of this process see Money Matters.
The purpose of a Needs Assessment is to identify what equipment, software or study support will enable you to fulfill your potential on your course of study. The assessment takes about 2 hours. The report will be emailed to you for approval and then sent to your funding body and to the Disability and Well-being Service at LSE. The whole process takes about 4 months.