Well first I would ask what happened to make you want to switch agents.... Is there a particular event that caused the mistrust? Have you tried talking to your agent? Hopefully you can work things out by really talking with each other about what is bothering you. If you feel the agent is not able to respresent you in the best manner, you may also want to see if there is another agent from the same office that your current agent can bring in to help out. Just an idea....
If you still feel like you would prefer to work with a different agent, you would need to cancel the contract with the agent you wrote the offer with and you would need to located another Realtor to represent you to submit another offer for the property. Depending on where you are in the process of haveing an accepted or declined offer, you may want to stay with the agent you are currently working with.
If this property does not work out for you, and you still feel that you would prefer to work with a different agent, I would, in writing, let your current agent know why you are terminating the relationship and work on finding someone who might be a better fit for you.
Hope this helps!
Alain Pinel Relators