Good morning Reuben,
You have got a rather large clump of Nerine Bowdenii bulbs there, these are delightful as they are pretty much the last bulb to flower in the garden usually in September/October.
They are rather overcrowded and will benefit from being divided up, but you will have to wait until Spring to split them up. They love a well drained, sheltered sunny spot and full sun is necessary so you will have to consider where you move them to with care. When you do divide them you must replant them straight away with their necks above the surface in a mix of compost and grit.
This Gardeners World link will show you how to do it http://www.gardenersworld.com/how-to/projects/pruning-training/how-to-lift-and-divide-nerines/218.html
I have got mine as home in pots, this way I can move them into the forefront at the end of the season and stand them in the sunniest spot. These Long Tom Terracotta pots would be ideal if you decide to use pots.
Good luck with your Nerines.