#include<bits/stdc++.h>
using namespace std;
const int N=105;
mt19937 rnd(0x66ccff);
int T,n,m;
char s[N][N],t[N][N];
#define For for(int i=0;i<2;++i)for(int j=0;j<2;++j)
int dx[8]={1,1,1,0,0,-1,-1,-1},dy[8]={1,0,-1,1,-1,1,0,-1};
void chg(char &c){
	if(c=='?')return;
	if(c=='B')c='W';
	else c='B';
}
bool bad(int x,int y){
	if(s[x][y]=='?')return false;
	For if(s[x+i][y+j]!=s[x][y])return false;
	return true;
}
bool Check(int x,int y){
	if(x==n||y==m||x<1||y<1)return false;
	int c=0;
	char v='?';
	For if(s[x+i][y+j]!='?')++c,v=s[x+i][y+j];
	if(c!=3)return false;
	For if(s[x+i][y+j]!='?'&&s[x+i][y+j]!=v)return false;
	chg(v);
	For if(s[x+i][y+j]=='?')s[x+i][y+j]=v;
	return true;
}
bool check(int x,int y){
	if(s[x][y]!='?')return false;
	For if(Check(x-i,y-j))return true;
	return false;
}
bool check(){
	for(int i=1;i<n;++i)for(int j=1;j<m;++j)if(bad(i,j))return false;
	return true;
}
void solve(){
	scanf("%d%d",&n,&m);
	for(int i=1;i<=n;++i)scanf("%s",s[i]+1);
	for(int i=1;i<=n;++i)for(int j=1;j<=m;++j)if(i+j&1)chg(s[i][j]);
	queue<pair<int,int> >q;
	int ct=0;
	for(int i=1;i<=n;++i)for(int j=1;j<=m;++j)if(s[i][j]!='?')++ct,q.push(make_pair(i,j));
	while(!q.empty()){
		auto [x,y]=q.front();
		q.pop();
		for(int i=0;i<8;++i){
			int u=x+dx[i],v=y+dy[i];
			if(u<1||u>n||y<1||y>m)continue;
			if(check(u,v))++ct,q.push(make_pair(u,v));
		}
	}
	if(!check())return puts("NO"),void();
	while(1){
		int cnt=ct;
		memcpy(t,s,sizeof(s));
		vector<pair<int,int> >e;
		for(int i=1;i<=n;++i)for(int j=1;j<=m;++j)if(s[i][j]=='?')e.push_back(make_pair(i,j));
		shuffle(e.begin(),e.end(),rnd);
		while(ct<n*m){
			if(q.empty()){
				while(s[e.back().first][e.back().second]!='?')e.pop_back();
				s[e.back().first][e.back().second]=rnd()&1?'W':'B',++ct;
				q.push(e.back());
			}
			auto [x,y]=q.front();
			q.pop();
			for(int i=0;i<8;++i){
				int u=x+dx[i],v=y+dy[i];
				if(u<1||u>n||y<1||y>m)continue;
				if(check(u,v))++ct,q.push(make_pair(u,v));
			}
		}
		if(check())break;
		ct=cnt,memcpy(s,t,sizeof(t));
	}
	puts("YES");
	for(int i=1;i<=n;++i)for(int j=1;j<=m;++j)if(i+j&1)chg(s[i][j]);
	for(int i=1;i<=n;++i){
		for(int j=1;j<=m;++j)putchar(s[i][j]);
		putchar(10);
	}
}
int main(){
	scanf("%d",&T);
	while(T--)solve();
	return 0;
}