No you can just change the modules inplace.
If m is the top module, you should be able to do m.features[2] = NewActivation() to change the first relu called relu0 there.
Then you can do the same for all relus.
Be careful when changing the BatchNorm, They have some learnable parameters and some statistics. If you remove these, you might see a drop in performance if you’re using the trained version of the model.