partition a graph using .gml file with digraph as input

I have a data in .gml format which is a digraph. I need to treat the digraph as an undirected graph by reciprocating all edges and to compute a partition of the graph into 2 communities using spectral methods to optimize the following quality functions:

a) The ratio cut.

b) The normalized cut.

c) The modularity.

I'm unable to figure out a way to get this done. Any help would be much appreciated.

Thanks