You might find it helpful to book an individual advice session with a Study Adviser for an initial chat. We can talk to you about study strategies, explain the 'reasonable adjustments' available to students with dyslexia or dyspraxia, and give you some information about the assessment process.
The Disability Advisory Service can provide more detailed information about assessment availability, costs and the assessment process itself.
For other specific learning difficulties like dyscalculia and AD(H)D, contact the Disability Advisory Service directly to find out how to get assessment and advice.
Make sure you get any 'reasonable adjustments' that you may be entitled to by submitting a copy of your assessment to the Disability Advisory Service as soon as possible. Don't wait until just before exams to do this - it can take some time to get adjustments put in place, especially at busy periods.
Do also come and have a chat with a Study Adviser - even if you have good strategies that have been effective through school and college, you are likely to need to develop them for university study.
If you have been diagnosed with, or think you may have Asperger Syndrome, contact the Disability Advisory Service for more advice.