If you do, then dont worry about getting cut up, you may get a bruise or just be sore for a few, but at least you wont be getting sliced up from your pedals.
You can also try learning 180 jump mounts, spin the uni 180 and jump onto it at the same time, and land SIF, so you have less chance of racking yourself, then once you get used to those, just try a unispin. =p
you skipped the 180 mount coz it was to hard lol the whole point of learning how 2 do it is because its a step 2 learning uni spins
I learned by:
hold the uni with pedals level learn to jump mount and land with SIF (should take only a few attempts to get it right)
2.practice how your going to spin the uni then learn 180 jump mounts (if your good at jump mounts it should only take a few attemps to land)
3.get on ur uni get SIF and just try and put it together, remember to throw your feet in then you just need to concentrate on keeping the uni under you if it goes out in front of you just move it under you a bit (this will take longer, just were pads and keep trying)
This worked well for me and i could do it within a few days the hardest bit I found was geting the uni in the right place under me so just conentrate on it