UCAS Application Entry Requirements

Hi i am due to take an assessment for english and maths tomorrow for the Access to health professionals course.
I made an enquiry to the Essex University regarding entry requirements, which they have responded " we would consider applicants with the Access to Higher Education Diploma in a relevant subject and would typically ask for 45 level 3 credits at Merit or above".
My question is? Is this quite easy to achieve or really hard?*
And with regards to the relevant subject, do they mean like the access to health professionals?.
I am not that young and do not have time to waste on a year long course that i could end up being refused entry into university because i do not have the relevant grades etc.
Any advise or personal experience would be much appreciated.

But for uni i would like to apply for the General Nursing.