#include <bits/stdc++.h>
using namespace std;
namespace Slongod{
const int N = 105;
const int dx[4] = {-1 , -1 , 0 , 0};
const int dy[4] = {-1 , 0 , -1 , 0};
vector <string> a; int n , m;
bool check(int x , int y)
{
    for (int op = 0; op < 4; op++) {
        int tx = x + dx[op] , ty = y + dy[op] , cnt = 0;
        if (tx < 1 or tx >= n or ty < 1 or ty >= m){continue;}

        //判断其他三个是否都确定了
        for (int i = 0; i < 4; i++) {
            int dtx = tx - dx[i] , dty = ty - dy[i];
            if (dtx != x or dty != y){cnt += (a[dtx][dty] == '?');}
        } if (cnt){continue;}

        if (op == 0) {
            if (a[tx+1][ty] == a[tx][ty+1] and a[tx][ty] != a[tx][ty+1]) {
                if (a[x][y] == a[tx][ty]){return false;}
                a[x][y] = a[tx+1][ty];
            }
        }
        if (op == 1) {
            if (a[tx][ty] == a[tx+1][ty+1] and a[tx][ty] != a[tx][ty+1]) {
                if (a[x][y] == a[tx][ty+1]){return false;}
                a[x][y] = a[tx][ty];
            }
        }
        if (op == 2) {
            if (a[tx][ty] == a[tx+1][ty+1] and a[tx][ty] != a[tx+1][ty]) {
                if (a[x][y] == a[tx+1][ty]){return false;}
                a[x][y] = a[tx][ty];
            }
        }
        if (op == 3) {
            if (a[tx+1][ty] == a[tx][ty+1] and a[tx+1][ty] != a[tx+1][ty+1]) {
                if (a[x][y] == a[tx+1][ty+1]){return false;}
                a[x][y] = a[tx+1][ty];
            }
        }
    } return true;
}
mt19937 rd(time(nullptr));
void main()
{
    int T; cin >> T;
    while(T--) {
        cin >> n >> m; a.clear(); a.push_back("Look at this \\rightarrow");
        for (int i = 1; i <= n; i++) {
            string s; cin >> s; a.push_back(" " + s);
        } bool f = true;
        for (int i =    1; i <= n; i++) {
            for (int j = 1; j <= m; j++) {
                f &= check(i , j);
            }
        }
        for (int i = n; i >= 1; i--) {
            for (int j = m; j >= 1; j--) {
                f &= check(i , j);
            }
        }
        if (!f){cout << "NO\n"; continue;}
        while(true) {
            auto back_up = a; f = true;
            for (int i = 1; i <= n; i++) {
                for (int j = 1; j <= m; j++) {
                    f &= check(i , j);
                    if (a[i][j] == '?') {
                        a[i][j] = ((rd() & 1) ? 'B' : 'W');
                    }
                }
            }
            for (int i = 1; i <= n; i++) {
                for (int j = 1; j <= m; j++) {
                    f &= check(i , j);
                }
            }
            if (f){break;} a = back_up;
        }
        cout << "YES\n";
        for (int i = 1; i <= n; i++) {
            for (int j = 1; j <= m; j++) {
                cout << a[i][j];
            } cout << '\n';
        }
    }
}
}int main()
{
    #ifndef ONLINE_JUDGE
    freopen("in.in" , "r" , stdin);
    #endif
    ios :: sync_with_stdio(0);
    cin.tie(0) , cout.tie(0);
    return Slongod :: main(),0;
}