System: win 10

Game: gta5 1.2.6

Step 1: First open the mod game map and find the location of the police station, as shown below:

Step 2: Arrive at the destination and choose to communicate with the police, as shown below:

Step 3: After the communication, enter the dressing room of the police station and find the change bag, as shown in the following figure:

Step 4: Choose to wear police uniform, as shown below: