Can I convert nonnegative decision variables into integer variables in an optimization model?

I have created this optimization model and I have two sets of decision variables.

    IloModel model(env);
    IloCplex cplex(model);
    IloObjective obj = IloMinimize(env);
    NumVarArray2 x = CreateNumVarArray2(env, N, M, "x", 0, 1);
    IloNumVarArray y = CreateNumVarArray(env, N, "y", 0, 1);

At first i am solving the LP Relaxation of the model. For those who are interested in, this is a part of a Branch-and-Price algorithm.

At the end of the algorithm, i need to convert my decision variables into binary variables to obtain an integer solution. Creating the model from scratch is a bit troublesome, so i am wondering if there is an easy way to do this.

Thanks in advance.