Arr=[5 5 5 5 ; 5 5 5 5; 5 5 5 5 ; 5 5 5 5; 5 5 5 5];
% First column number change the 10
Arr(:,1)=10
%Do the same for others
Result:
Arr =
10 5 5 5
10 5 5 5
10 5 5 5
10 5 5 5
10 5 5 5
You can do multiple column elements change with single assignments also