According to Section 140 of the Civil Procedure Law, you have the right to submit an application to the court, which rendered the decision regarding securing the claim, requesting to remove the attachment. However, the application shall be reasonable. Securing of a claim may be used in case, if there is a reason to believe that the execution of a court judgment in a matter may become impossible. Therefore you need to prove that you will be able to execute the judgment, and this can be done by arguing against the reasons of the plaintiff for securing the claim, etc. Your application will be considered at a court sitting, where you will have the opportunity to explain your position in detail.