Drop-in maths help in the first "technobooth" in the Drill Hall Library cafe (Archibald Hay Mess).
There is no need to book - you just turn up (but bring your lecture notes!). A tutor will help you understand the maths or stats that you need, whatever its level. (If the materialis very specialist - for example, the advanced statistics sometimes required by a PhD student - it would be helpful to have advance notice of the problem.)
No need to book - just turn up.