How can I change a specific layer of 3D ResNet-18?

I am having a lot of trouble trying to change the stride of the Conv3DSimple layer on the 9th line. This snippet allows me to change the first Conv3d layer

modules = list(self.encoder.children())
modules[0] = nn.Conv3d(3, 64, kernel_size=(3, 7, 7), stride=(1, 1,1), padding=(1, 3, 3), bias=False)

but modules[3] does not give me a single layer. How can I access a specific layer?

[BasicStem(
  (0): Conv3d(3, 64, kernel_size=(3, 7, 7), stride=(1, 2, 2), padding=(1, 3, 3), bias=False)
  (1): BatchNorm3d(64, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
  (2): ReLU(inplace=True)
), Sequential(
  (0): BasicBlock(
    (conv1): Sequential(
      ### How do I change the stride to (1,2,2) ?
      (0): Conv3DSimple(64, 64, kernel_size=(3, 3, 3), stride=(1, 1, 1), padding=(1, 1, 1), bias=False)
      ### How do I change the stride to (1,2,2) ?
      (1): BatchNorm3d(64, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (2): ReLU(inplace=True)
    )
    (conv2): Sequential(
      (0): Conv3DSimple(64, 64, kernel_size=(3, 3, 3), stride=(1, 1, 1), padding=(1, 1, 1), bias=False)
      (1): BatchNorm3d(64, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
    )
    (relu): ReLU(inplace=True)
  )
  (1): BasicBlock(
    (conv1): Sequential(
      (0): Conv3DSimple(64, 64, kernel_size=(3, 3, 3), stride=(1, 1, 1), padding=(1, 1, 1), bias=False)
      (1): BatchNorm3d(64, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (2): ReLU(inplace=True)
    )
    (conv2): Sequential(
      (0): Conv3DSimple(64, 64, kernel_size=(3, 3, 3), stride=(1, 1, 1), padding=(1, 1, 1), bias=False)
      (1): BatchNorm3d(64, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
    )
    (relu): ReLU(inplace=True)
  )
), Sequential(
  (0): BasicBlock(
    (conv1): Sequential(
      (0): Conv3DSimple(64, 128, kernel_size=(3, 3, 3), stride=(2, 2, 2), padding=(1, 1, 1), bias=False)
      (1): BatchNorm3d(128, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (2): ReLU(inplace=True)
    )
    (conv2): Sequential(
      (0): Conv3DSimple(128, 128, kernel_size=(3, 3, 3), stride=(1, 1, 1), padding=(1, 1, 1), bias=False)
      (1): BatchNorm3d(128, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
    )
    (relu): ReLU(inplace=True)
    (downsample): Sequential(
      (0): Conv3d(64, 128, kernel_size=(1, 1, 1), stride=(2, 2, 2), bias=False)
      (1): BatchNorm3d(128, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
    )
  )
  (1): BasicBlock(
    (conv1): Sequential(
      (0): Conv3DSimple(128, 128, kernel_size=(3, 3, 3), stride=(1, 1, 1), padding=(1, 1, 1), bias=False)
      (1): BatchNorm3d(128, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (2): ReLU(inplace=True)
    )
    (conv2): Sequential(
      (0): Conv3DSimple(128, 128, kernel_size=(3, 3, 3), stride=(1, 1, 1), padding=(1, 1, 1), bias=False)
      (1): BatchNorm3d(128, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
    )
    (relu): ReLU(inplace=True)
  )
), Sequential(
  (0): BasicBlock(
    (conv1): Sequential(
      (0): Conv3DSimple(128, 256, kernel_size=(3, 3, 3), stride=(2, 2, 2), padding=(1, 1, 1), bias=False)
      (1): BatchNorm3d(256, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (2): ReLU(inplace=True)
    )
    (conv2): Sequential(
      (0): Conv3DSimple(256, 256, kernel_size=(3, 3, 3), stride=(1, 1, 1), padding=(1, 1, 1), bias=False)
      (1): BatchNorm3d(256, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
    )
    (relu): ReLU(inplace=True)
    (downsample): Sequential(
      (0): Conv3d(128, 256, kernel_size=(1, 1, 1), stride=(2, 2, 2), bias=False)
      (1): BatchNorm3d(256, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
    )
  )
  (1): BasicBlock(
    (conv1): Sequential(
      (0): Conv3DSimple(256, 256, kernel_size=(3, 3, 3), stride=(1, 1, 1), padding=(1, 1, 1), bias=False)
      (1): BatchNorm3d(256, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (2): ReLU(inplace=True)
    )
    (conv2): Sequential(
      (0): Conv3DSimple(256, 256, kernel_size=(3, 3, 3), stride=(1, 1, 1), padding=(1, 1, 1), bias=False)
      (1): BatchNorm3d(256, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
    )
    (relu): ReLU(inplace=True)
  )
), Sequential(
  (0): BasicBlock(
    (conv1): Sequential(
      (0): Conv3DSimple(256, 512, kernel_size=(3, 3, 3), stride=(2, 2, 2), padding=(1, 1, 1), bias=False)
      (1): BatchNorm3d(512, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (2): ReLU(inplace=True)
    )
    (conv2): Sequential(
      (0): Conv3DSimple(512, 512, kernel_size=(3, 3, 3), stride=(1, 1, 1), padding=(1, 1, 1), bias=False)
      (1): BatchNorm3d(512, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
    )
    (relu): ReLU(inplace=True)
    (downsample): Sequential(
      (0): Conv3d(256, 512, kernel_size=(1, 1, 1), stride=(2, 2, 2), bias=False)
      (1): BatchNorm3d(512, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
    )
  )
  (1): BasicBlock(
    (conv1): Sequential(
      (0): Conv3DSimple(512, 512, kernel_size=(3, 3, 3), stride=(1, 1, 1), padding=(1, 1, 1), bias=False)
      (1): BatchNorm3d(512, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (2): ReLU(inplace=True)
    )
    (conv2): Sequential(
      (0): Conv3DSimple(512, 512, kernel_size=(3, 3, 3), stride=(1, 1, 1), padding=(1, 1, 1), bias=False)
      (1): BatchNorm3d(512, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
    )
    (relu): ReLU(inplace=True)
  )
), AdaptiveAvgPool3d(output_size=(1, 1, 1)), Linear(in_features=512, out_features=400, bias=True)]