With the increase of attacks and Information Systems getting ever more complex, security operators need tools to help them protecting critical assets. An attack graph is a model to assess the level of security of an Information System, but it can be used to compute actions that mitigate the modeled threats. In this paper we present a method to remediate the most relevant attack paths extracted from a logical attack graph. In order to help an operator to choose between several remediation candidates, we rank them according to a cost of remediation combining operational and impact costs. We implement this method using MulVAL attack graphs and several publicly available sets of data.