We study a meta-module based tunneling reconfiguration algorithm for sliding cubic modular robots. Tunneling modular robots are suitable for missions in environments with limited spaces; however, they require a meta-module to maintain their connectivity and mobility. During the tunneling process, the meta-modules often come apart, and each module belongs to the different meta-module before and after the reconfiguration. We propose a method avoiding this. We briefly show that the method is complete and that the reconfiguration is executed in quadratic operating time cost.