Brushing boot question

[Marnie]

I have just bought some Sportbac neoprene brushing boots for my mare. She has quite a lot of bone, but her canon bones are short. I had to buy the medium for her fronts and large for her back, they fit beautifully around her legs but are just slightly too long. Is it possible to trim neoprene without it fraying or anything, has anyone tried it? They are very soft and so would be ok without trimming but would just fit that bit better.

Any ideas?

Thanks!