Just wait till the weather warms up in spring, around April May time, then cut off anything which looks tatty or brown or torn, removing as close to the base as possible.

I agree with Bamboo but add that the lower leaves die back naturally to form the trunk.

O.K, thanks you two. Will wait until Spring and re-evaluate.

Hi bamboo ,i was told they wasnt hardy so i put mine in the house,its not done well at all!, ive hacked all brown leaves off and moved it to the bathroom where it seems to be getting its colour back slowly:O) will i be able to move it to the greenhouse do you think?? thanks julie x
Sorry alex,dont mean to gate crash your post :O) x

Some varieties are hardier than others, but most will survive a reasonable winter - its when we have a harsh winter throughout that you're at risk of losing them, even in the ground.
If its been in the house and used to heat, unless your greenhouse is heated, it might be a bit of a shock for it. As we're almost through the worst of the winter, I'd wait till end of February with it in the house, then start hardening it off ready to leave outside permanently. Do that by standing it outside for a couple of hours in the middle of the day, extending the time its out over a week or so until it is out all night as well, though preferably not a suddenly bitter cold night. You could leave it in the cold greenhouse for its first night or two before finally leaving exposed to the elements all night as well. Repot if it needs it end of March or April.

Thanks bamboo,in the bathroom it stays then :O)