You basically need to access the right parameters and set them to 0. Then set their property .requires_grad = False to make sure they don’t change in value.
The way to access weights in PyTorch is to use .parameters() function. Any model’s children can be accessed using model.children().
for child in model.children():
    for param in child.parameters():
        <access specific parameters and set them to 0, and set requires_grad to False>

Hope this helps!