Modifying a tuple in a vector of tuples c++

I have a vector of tuples vector<tuple<int,int>> vector; and I want to modify one of the tuples it contains.

for (std::tuple<int, int> tup : std::vector)
{
    if (get<0>(tup) == k)
    {
        /* change get<1>(tup) to a new value
         * and have that change shown in the vector
         */
    }
}

I am unsure how to change the value of the tuple and have the change be reflected in the vector. I have tried using

get<1>(tup) = v;

but that doesn't change the value of the tuple that is in the vector. How can I do this? Thanks.