Are the conditions imposed by police or the courts?
If they were set by police, they can be varied by any custody officer at the police station at which they were set originally or at any court. However bear in mind that its is not a guarantee that the conditions will be changed, and the court or Custody Officer have the option of making the conditions more stringent as well as varying or making them more lenient. They could, in fact, cancel the bail and keep someone in custody. I'm not syaing this to put you off, but it's worth taking advice before making the application to make sure you're not going to land yourself in difficulties.