String groupId = utils.readString(session.getNodeByUUID(oldGroupUUID), MigrationTool.JOS_GROUP_ID);
String membershipTypeName = session.getNodeByUUID(oldMembershipTypeUUID).getName();
User user = service.getUserHandler().findUserByName(userName);
Group group = service.getGroupHandler().findGroupById(groupId);
MembershipType mt = service.getMembershipTypeHandler().findMembershipType(membershipTypeName);
Membership existingMembership = findMembershipByUserGroupAndType(userName, groupId, membershipTypeName);
if (existingMembership != null)
{
removeMembership(existingMembership.getId(), false);