Yes you can, I changed after my booking appointment and don't regret it at all. I do have to drive to the surgery in the next village to see the new midwife, but as it's only a ten minute drive (and 10 mins anyway in the other direction to our original surgery) it's not that much of a problem for me. The original midwife was awful, really insensitive, rude, kept answering phonecalls from her adult daughter during my appointment (about really inane things, her daughter spoke very loudly so I could hear every word!), acted very bored the whole time, the list goes on.
I told her I wasn't happy and asked for the names of the other community midwives in our area, I said I would either transfer myself or speak to the supervisor of midwives to get transferred, and she quickly agreed to let me transfer myself.
I phoned the other midwives and asked if they would take on my care (very little to do as mostly consultant-led) one said her books were pretty full but she would if the other couldn't, and the other said yes straight away. Our new midwife is amazing, she is so lovely, caring and thorough. She always seems pleased to hear from me even for minor things and never makes me feel like I'm any trouble, so much so that DH and I are trying to get the consultant to agree to having her at the birth rather than one of the hospital midwives.
I was also told that you can see one of the hospital midwives instead of a community one, but that you would need to speak to the head midwife at the hospital about it. Out hospital are great and very laid back, so not sure if that is standard policy.