if i have a code for genetic algorithm but its need some alter how to do them?

i have this code for genetic algorithm

    % i need a minimum value for the fitness function
    %nPop = 10 , MaxIt = 100
    % pc = 0.6;                     % Crossover Percentage
    % nc = 2*round(pc*nPop/2);      % Number Of offsprings (also Parents)

 %%generate populations 
Matrix_pop = [];
val = [];
for k=1 : nPop    % 10 is the population size
  Matrix_pop{k} = randi ([0 1] , 10,10)  % create a binary (10,10) matrix 
   fit = sum(sum(Matrix_pop{k}));  % fitness function is compute the total number of ones in Matrix.
   val(k) = fit ; 
 end
 value = sort(val , 'ascend');

%%Main algorithm 

for it=1:MaxIt           %maximum number of iteration 

      for i=1: nc/2       % number of parent
         for k=1 : value.length 
        i1 = ([1 k]);
        i2 = ([1 k+1]);

        p1=Matrix_pop{i1};
        p2=Matrix_pop{i2};

after this how can i perform the crossover and mutation and create a new population to get the minimum value for the fitness function and after that the solution will display as the matrix which have the minimum value ????

can any one give me help , thank you