Thanks for the tag.
Alright, so it's definitely possible - now how easy you'll find it is a different story. You could feel like it's a breeze or struggle through it really hard. Assuming that you're leaning more towards the latter then it's important that
(i) You get all administrative business out of the way so you don't stress: get your exam timetable, make sure you're registered for the exam at a centre, etc...
(ii) Have a good work ethic, set yourself targets everyday: "I need to have learnt logarithms and gone through the first exercise on it by the end of the day"' - stuff like that.
(iii) Ask for help on TSR/to your teachers whenever you are stuck. Never go "meh, I don't understand but it probs won't come up so nvm".
(iv) Use examsolutions, it is a
lifesaver. Now depending on how good you are, you can relax some of these things. But to be safe, I'd recommend following it. I personally had a really crappy work ethic which came to bite me in the ass for STEP (although I still somehow managed to do well... so that that how you will - there was certainly a lot of stress about my STEP II paper pre-results day).
Good luck. Feel free to contact me whenever for advice/help.